U.S. patent application number 13/348871 was filed with the patent office on 2012-07-19 for firearm.
This patent application is currently assigned to ArmWest, LLC.. Invention is credited to Paul N. Latulippe, JR., James McGarry, Leroy James Sullivan, Robert Lloyd Waterfield.
Application Number | 20120180648 13/348871 |
Document ID | / |
Family ID | 46489755 |
Filed Date | 2012-07-19 |
United States Patent
Application |
20120180648 |
Kind Code |
A1 |
Sullivan; Leroy James ; et
al. |
July 19, 2012 |
FIREARM
Abstract
A firearm can have a bolt having a plurality of locking lugs
that are configured to have a shear area that is at least
approximately 1.3 times that of a standard M16/M4. A piston can be
formed on the bolt and can have a plurality of rings that are
configured to cooperate with the piston to mitigate gas leakage
past the piston. Each of the rings can have a key formed thereon
and a gap formed therein such that the gap of one ring is
configured to receive at least a portion of the key of another
ring. The bolt carrier can have a double cut cam.
Inventors: |
Sullivan; Leroy James;
(Prescott, AZ) ; McGarry; James; (Prescott,
AZ) ; Waterfield; Robert Lloyd; (Prescott, AZ)
; Latulippe, JR.; Paul N.; (Chino Valley, AZ) |
Assignee: |
ArmWest, LLC.
Prescott
AZ
|
Family ID: |
46489755 |
Appl. No.: |
13/348871 |
Filed: |
January 12, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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61433092 |
Jan 14, 2011 |
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61433083 |
Jan 14, 2011 |
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61478439 |
Apr 22, 2011 |
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61479194 |
Apr 26, 2011 |
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61498426 |
Jun 17, 2011 |
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61528062 |
Aug 26, 2011 |
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Current U.S.
Class: |
89/193 |
Current CPC
Class: |
F41A 3/26 20130101; F41A
3/70 20130101; F41A 5/18 20130101; F41A 5/26 20130101; F16J 9/16
20130101; F41A 5/24 20130101; F41A 5/28 20130101; F41A 21/24
20130101; F41A 13/12 20130101; F41A 3/14 20130101 |
Class at
Publication: |
89/193 |
International
Class: |
F41A 5/26 20060101
F41A005/26; F41A 3/30 20060101 F41A003/30 |
Claims
1. A firearm comprising: a bolt having a plurality of locking lugs,
the locking lugs being configured to have a shear area that is at
least approximately 1.3 times that of a standard M16/M4; a piston
formed on the bolt and having a plurality of rings configured to
cooperate with the piston to mitigate gas leakage past the piston,
each of the rings having a key formed thereon and a gap formed
therein such that the gap of one ring is configured to receive at
least a portion of the key of another ring; a bolt carrier to which
the bolt is movably attached, the bolt carrier having a double cut
cam, the double cut cam having a starting point in an unlocked
position of the bolt that is substantially the same as the standard
M16 cam and having an unlocking cam surface that has sufficient
dwell increase to delay a start of unlocking when the bolt carrier
is used in an M16/M4 rifle or carbine; a weight movably disposed
within the bolt carrier, the weight being configured to inhibit
rearward and forward bouncing of the bolt carrier; a carrier key
attached to the bolt carrier and configured to facilitate a stroke
of the bolt carrier that is approximately 0.360 inch longer than
that of the standard M16/M4; a buffer having a length that is
approximately 0.360 inch shorter than a standard buffer for the
M16/M4 buffer; a tube configured to provide gas from a barrel of
the firearm to the piston via the carrier key, the tube having a
heat radiator formed on at least a portion of the tube; a gas
metering plug having a gas metering hole configured to meter gas
from the barrel of a firearm to the bolt carrier of the firearm,
wherein the gas metering hole is located away from a gas port of
the firearm; and a front sight block having a rear band and a front
band for attaching the sight block to the barrel and having a gas
passage formed in the front band for facilitating gas flow from the
barrel to a gas tube of the firearm. A bolt group comprising: a
bolt having a plurality of locking lugs, the locking lugs being
configured to have a shear area that is at least approximately 1.3
times that of a standard M16/M4; a piston formed on the bolt and
having a plurality of rings configured to cooperate with the piston
to mitigate gas leakage past the piston, each of the rings having a
key formed thereon and a gap formed therein such that the gap of
one ring is configured to receive at least a portion of the key of
another ring; a bolt carrier to which the bolt is movably attached,
the bolt carrier having a double cut cam, the double cut cam having
a starting point in an unlocked position of the bolt that is
substantially the same as the standard M16 cam and having an
unlocking cam surface that has sufficient dwell increase to delay a
start of unlocking when the bolt carrier is used in an M16 rifle or
an M4 carbine; a weight movably disposed within the bolt carrier,
the weight being configured to inhibit rearward and forward
bouncing of the bolt carrier; and a carrier key attached to the
bolt carrier and configured to facilitate a stroke of the bolt
carrier that is approximately 0.360 inch longer than that of the
standard M16/M4.
3. A device comprising: a ring configured to cooperate with a
piston of a gas operated firearm to mitigate gas leakage past the
piston; a key formed upon the ring; and a gap formed in the ring
and configured to receive at least a portion of a key of another
ring.
4. The device as recited in claim 3, wherein the key is
substantially opposite the gap on the ring.
5. The device as recited in claim 3, wherein the key and the gap
are formed such that a pair of the rings is nestable with the key
of each of the rings disposed within the gap of each other of the
rings.
6. The device as recited in claim 3, wherein the key is
substantially rectangular in cross-section.
7. The device as recited in claim 3, wherein the gap is
substantially rectangular in cross-section.
8. The device as recited in claim 3, wherein the walls of the ring
are substantially rectangular in cross-section.
9. The device as recited in claim 3, wherein the ring is formed of
stainless steel.
10. The device as recited in claim 3, wherein the ring is
configured to be received at least partially within a groove of the
piston.
11. The device as recited in claim 3, wherein the device is a
firearm.
12. A device comprising: a piston for a gas operated firearm; a
first ring configured to be received on the piston; a second ring
configured to be received on the piston; and wherein the first ring
and second ring are configured to interlock with one another such
that the first ring and second ring rotate substantially in unison
about the piston.
13. A method comprising: placing one ring having a key and a gap on
a piston of a gas operated firearm; placing another ring having a
key and a gap on the piston; and wherein the key of each one of the
rings is disposed at least partially within the gap of each of the
other rings.
14. A method comprising: mitigating gas leakage past a piston of a
firearm using a plurality of rings, each one of the rings having a
key formed thereon and a gap formed therein; and wherein the gap of
one of the rings receives at least a portion of the key of another
of the rings.
Description
PRIORITY CLAIM
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/433,092, filed Jan. 14, 2011. This application
claims the benefit of U.S. Provisional Application No. 61/433,083,
filed Jan. 14, 2011. This application claims the benefit of U.S.
Provisional Application No. 61/478,439, filed Apr. 22, 2011. This
application claims the benefit of U.S. Provisional Application No.
61/479,194, filed Apr. 26, 2011. This application claims the
benefit of U.S. Provisional Application No. 61/498,426, filed Jun.
17, 2011. This application claims the benefit of U.S. Provisional
Application No. 61/528,062, filed Aug. 26, 2011. All of these
provisional patent applications are hereby incorporated by
reference in their entirety.
TECHNICAL FIELD
[0002] One or more embodiments of the invention relate generally to
firearms and, more particularly for example, to a firearm such as a
member of the M16/M4 family of firearms that has features which
enhance the reliability thereof.
BACKGROUND
[0003] The M16 service rifle and the M4 carbine are well known.
Although these firearms have proven generally satisfactory, the M16
and M4, as well as other firearms, have a variety of reliability
shortcomings. These reliability shortcomings can result in a
malfunction of the firearm. These reliability shortcomings are
becoming more evident as the use of higher capacity magazines
increases. Such malfunctions can have serious consequences and are
thus highly undesirable. Some of the reliability shortcomings are
discussed below.
[0004] Gas operated firearms use some of the gas from a cartridge
being fired to extract the spent case of the cartridge and to
chamber a new cartridge. The gas travels from a port in the barrel
to a gas cylinder where the gas pushes a piston within the gas
cylinder to operate a mechanism for extracting the spent case and
for chambering the new cartridge. In some firearms, such as the M16
and the M4, the gas cylinder is formed in the bolt carrier and the
piston is part of the bolt. In such firearms, gas is provided from
the barrel to the gas cylinder by a gas tube.
[0005] In other firearms, such as the HK416, a separate (not part
of the bolt) piston is used. The piston is disposed in a gas
cylinder that is not part of the bolt carrier. This separate piston
applies force through a tappet or operating rod and a bolt carrier
to operate the mechanism for extracting the spent case and for
chambering the new cartridge.
[0006] Whether or not the piston is part of the bolt, it is
desirable to prevent gas leakage between the piston and the
cylinder. Contemporary gas operated firearms commonly use a
plurality of piston rings which fit into a groove of the piston in
an attempt to provide a gas seal between the piston and the
cylinder to mitigate gas leakage. For example, the M16, M4, and
HK416 use three rings. Each of the rings is a split ring that has a
gap formed therein to facilitate installation of the ring and to
allow the ring to apply an outward spring force that tends to seal
the loose fit between the piston and the cylinder.
[0007] Contemporary rings possess inherent deficiencies which
detract from their overall effectiveness and desirability. For
example, the gaps of the three rings occasionally line up in a
manner that allows hot gasses to flow readily through the gaps and
thereby undesirably bypass the rings. When the hot gases flow
through the gaps, the force provided by the gases to extract a
spent case from the chamber and to chamber a new cartridge is
undesirably reduced. Further, when the hot gases flow through the
gaps, the hot gases can burn the ends of the rings and thereby
undesirably enlarge the gaps. It is desirable to provide rings that
mitigate undesirable gas flow thereby.
[0008] Contemporary gas tubes possess inherent deficiencies which
detract from their effectiveness and desirability. For example,
contemporary gas tubes can overheat and lose strength, particularly
during sustained fully automatic fire of the firearm. The higher
level of heat associated with sustained fully automatic fire can
result in undesirable thermal expansion of the gas tube both
radially and longitudinally. Such thermal expansion can be
substantially beyond an amount that can be accommodated by the
available space in the firearm. Such thermal expansion can result
in sliding/clearance fits becoming interference fits. That is, a
sliding fit can undesirably become a non-sliding fit, i.e., can
freeze or jam. When the gas tube heats up excessively, the weakened
and expanded gas tube can bend and be damaged because it is not
free to slide, thus causing the firearm to become inoperative. It
is desirable to provide methods and systems for mitigating
overheating in gas operated firearms.
[0009] Forward and rearward bouncing of the bolt carrier can cause
the cyclic rate of a firearm to increase substantially. This
increase in the cyclic rate can reduce the reliability of the
firearm and can increased wear on the firearm. It is desirable to
provide methods and systems for mitigating both forward and
rearward bouncing of the bolt carrier.
[0010] The gas port of a contemporary M16/M4 firearm is subject to
erosion caused by bullet scrubbing and propellant bombardment. Such
erosion results in enlargement of the gas port and consequently an
undesirable increase in the cyclic rate of the firearm over time.
M4 carbines, which have the gas port located at a rear band of the
front sight, are particularly susceptible to such erosion. This
undesirable increase in the cyclic rate can eventually result in
malfunction and damage to the firearm. It is desirable to provide
for the placement of the gas port and metering of gas in a manner
that does not result in an increased cyclic rate over time.
[0011] Gas operated firearms, such as those of the M16/M4 family of
firearms, have bolt and barrel locking lugs that secure the bolt to
the barrel during firing. Failure of the locking lugs can result in
the firearm being inoperable. It is desirable to provide more
robust locking lugs for such firearms, so as to mitigate the
undesirable occurrence of failure.
[0012] The cam of a bolt carrier of such firearms cooperates with
the cam pin of the bolt to lock and unlock the locking lugs. In
instances where pressure of the gas system has increased and the
cyclic rate has consequently also increased, such as due to erosion
of the gas port, the cam can cooperate with the cam pin to attempt
to unlock the locking lugs too early in the firing cycle. In this
instance, the gas pressure in the chamber can be too high to allow
the locking lugs to rotate fully. When this happens, one or more of
the locking lugs can break. Again, this can result in the firearm
being inoperable, thereby potentially resulting in loss of life in
situations such as during police use and battlefield operations. It
is desirable to assure that the gas pressure in the chamber is
sufficiently low to allow the locking lugs to rotate fully when the
bolt is being unlocked.
[0013] These reliability shortcomings of such contemporary firearms
can result in the failure thereof. The failure of the firearm,
particularly during critical police use and battlefield operations,
can result in loss of life. Therefore, it is desirable to provide
firearms that do not suffer from these reliability
shortcomings.
BRIEF SUMMARY
[0014] In accordance with embodiments further described herein,
methods and systems are provided for enhancing the reliability of
firearms, such as firearms in the M16/M4 family of firearms. For
example, an embodiment can comprise a firearm having a bolt with a
plurality of locking lugs that are configured to have a shear area
that is at least approximately 1.3 times that of a standard M16/M4.
A piston can be formed on the bolt and can have a plurality of
rings that are configured to cooperate with the piston to mitigate
gas leakage past the piston. Each of the rings can have a key
formed thereon and a gap formed therein such that the gap of one
ring is configured to receive at least a portion of the key of
another ring. A bolt carrier can have the bolt movably attached
thereto. The bolt carrier can have a double cut cam. The double cut
cam can have a starting point in an unlocked position of the bolt
that is substantially the same as the standard M16 cam and can have
an unlocking cam surface that has sufficient dwell to increase to
delay a start of unlocking when the bolt carrier is used in an M4
carbine. Thus, the dwell can be increased with respect to an M4
carbine lacking a double cut cam. A weight can be movably disposed
within the bolt carrier. The weight can be configured to inhibit
rearward and forward bouncing of the bolt carrier. A long stroke
carrier key can be attached to the bolt carrier and can be
configured to facilitate a stroke of the bolt carrier that is
approximately 0.360 inch longer than that of a standard M16/M4. A
gas tube can be configured to provide gas from a barrel of the
firearm to the piston via the carrier key. The gas tube can have a
heat radiator formed on at least a portion of the gas tube. A gas
metering plug can have a gas metering hole configured to meter gas
from the barrel of the firearm to the bolt carrier of the firearm.
The gas metering hole can be located away from a gas port of the
firearm. A front sight block can have a rear band and a front band
for attaching the front sight block to the barrel and can have a
gas passage formed in the front band for facilitating gas flow from
the barrel to a gas tube of the firearm.
[0015] According to an embodiment, a bolt group can have a bolt
having a plurality of locking lugs. The locking lugs can be
configured to have a shear area that is at least approximately 1.3
times that of a standard M16/M4. A piston can be formed on the bolt
and can have a plurality of rings configured to cooperate with the
piston to mitigate gas leakage past the piston. Each of the rings
can have a key formed thereon and a gap formed therein such that
the gap of one ring is configured to receive at least a portion of
the key of another ring. A bolt carrier can have the bolt movably
attached thereto. The bolt carrier can have a double cut cam. The
double cut cam having a starting point in an unlocked position of
the bolt that is substantially the same as the standard M16 cam and
can have an unlocking cam surface that has sufficient dwell
increase to delay a start of unlocking when the bolt carrier is
used in an M4 carbine. Thus, the dwell can be increased with
respect to an M4 carbine lacking a double cut cam. A weight can be
movably disposed within the bolt carrier. The weight can be
configured to inhibit rearward and forward bouncing of the bolt
carrier. A carrier key can be attached to the bolt carrier and can
be configured to facilitate a stroke of the bolt carrier that is
approximately 0.360 inch longer than that of a standard M16/M4.
[0016] According to an embodiment, a ring can be configured to be
received at least partially within a groove of the piston. A key
can be formed upon the ring and a gap can be formed in the ring.
The gap of one ring can be configured to receive at least a portion
of the key of another ring. Thus, the rings can be interlocked such
they cannot rotate to a position where the gaps line up in a manner
that allows hot gasses to flow through the gaps.
[0017] According to an embodiment, a gas tube can be configured to
provide gas from a barrel of a firearm to a piston of the firearm.
A heat radiator can be formed on at least a portion of the gas
tube, according to an embodiment. The heat radiator can inhibit
overheating of the gas tube. The gas tube can be configured such
that thermal expansion does not cause the gas tube to bind or be
damaged by cycling of the firearm.
[0018] According to an embodiment, a device can comprise a gas
metering plug having a gas metering hole that is configured to
meter gas from a barrel of a firearm to a bolt carrier of the
firearm. The gas metering hole can be located away from a gas port
of the firearm, so as not to be subject to erosion caused by bullet
scrubbing and propellant bombardment.
[0019] According to an embodiment, undesirable forward and rearward
bouncing of a bolt carrier of a gas operated firearm can be
inhibited. For example, a device can have a bolt carrier and an
anti-bounce weight movably disposed within the bolt carrier. The
weight can be configured to inhibit both rearward and forward
bouncing of the bolt carrier.
[0020] According to an embodiment, a bolt carrier can have a double
cut cam formed therein. The double cut cam can have a starting
point in an unlocked position of the bolt that is substantially the
same as the standard M16 cam. The double cut cam can have an
unlocking cam surface that has sufficient dwell increase to delay a
start of unlocking when the bolt carrier is used in an M4
carbine.
[0021] According to an embodiment, a bolt and a barrel extension
for an M16/M4 firearm can have a plurality of locking lugs. The
locking lugs can be configured to have a shear area that is at
least approximately 1.3 times that of a standard M16/M4. A carrier
key can be configured to facilitate a stroke of the bolt carrier
that is approximately 0.360 inch longer than that of a standard
M16/M4. A buffer can be configured to limit travel of the bolt
carrier. The buffer can be approximately 0.360 inch shorter than
that of the standard M16/M4.
[0022] According to an embodiment, the gas port of a firearm can be
moved forward along the barrel so as to delay the time at which gas
acts upon the bolt of the firearm after a cartridge is fired and so
as to reduce the pressure of the gas acting upon the bolt. In this
manner, the cyclic rate of the firearm can be reduced and the
reliability of the firearm can be enhanced.
[0023] These features can cooperate to provide a safer, more
reliable firearm. For example, the long or extended locking lugs,
gas piston rings, and the gas tube can cooperate to make the gas
system of the firearm more robust. As a further example, the
anti-bounce weight, the gas metering plug, the gas passage in the
forward sight band and double cut cam can cooperate to reduce the
cyclic rate and to mitigate undesirable wear on the firearm.
[0024] The scope of the disclosure is defined by the claims, which
are incorporated into this section by reference. A more complete
understanding of embodiments will be afforded to those skilled in
the art, as well as a realization of additional advantages thereof,
by a consideration of the following detailed description of one or
more embodiments. Reference will be made to the appended sheets of
drawings that will first be described briefly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a perspective view of a bolt, such as for an
M16/M4, showing keyed piston rings exploded therefrom, according to
an embodiment.
[0026] FIG. 2 is an enlarged side view of a piston of FIG. 1 having
one keyed piston ring installed thereon and one keyed piston ring
partially installed thereon, according to an embodiment.
[0027] FIG. 3 is an enlarged perspective view of the piston of FIG.
1 having two keyed piston rings installed thereon, according to an
embodiment.
[0028] FIG. 4 is a perspective view of a piston, such as for a
HK416, showing keyed piston rings exploded therefrom, according to
an embodiment.
[0029] FIG. 5 is an enlarged side view of the piston of FIG. 4
having one keyed piston ring installed thereon and one keyed piston
ring partially installed thereon, according to an embodiment.
[0030] FIG. 6 is an enlarged perspective view of the piston of FIG.
4 having two keyed piston rings installed thereon, according to an
embodiment.
[0031] FIG. 7 is a perspective view of a firearm, such as an
M16/M4, having the bolt of FIG. 1, according to an embodiment.
[0032] FIG. 8 is a perspective view of a firearm, such as a HK416,
having the piston of FIG. 4, according to an embodiment.
[0033] FIG. 9 is side view of a heat dissipating gas tube for a
firearm, according to an embodiment.
[0034] FIGS. 10A-10C are cross-sectional views showing the heat
dissipating gas tube and a gas metering plug, according to an
embodiment.
[0035] FIG. 11 is a cross-sectional side view of a rear end of the
gas tube and a carrier key that receives the rear end of the gas
tube, according to an embodiment.
[0036] FIG. 12 is a flow chart showing a method for making a
firearm having a heat dissipating gas tube, according to an
embodiment.
[0037] FIG. 13 is a top view of a bolt carrier having an
anti-bounce assembly, according to an embodiment.
[0038] FIG. 14 is a side view of the bolt carrier of FIG. 13,
according to an embodiment.
[0039] FIG. 15 is an enlarged side view of the anti-bounce assembly
of FIG. 13 showing an anti-bounce weight in a zero or non-impact
position, according to an embodiment.
[0040] FIG. 16 is an enlarged side view of the anti-bounce assembly
of FIG. 13 showing the anti-bounce weight in a rearward impact
position, according to an embodiment.
[0041] FIG. 17 is an enlarged side view of the anti-bounce assembly
of FIG. 13 showing the anti-bounce weight in a forward impact
position, according to an embodiment.
[0042] FIG. 18 is an exploded view of the bolt carrier of FIG. 13,
according to an embodiment.
[0043] FIG. 19 is a top exploded view of plungers, springs, and the
anti-bounce weight of FIG. 18, according to an embodiment.
[0044] FIG. 20 is a perspective exploded view of the plungers, the
springs, and the anti-bounce weight of FIG. 18, according to an
embodiment.
[0045] FIG. 21 is a top assemble view of the plungers, the springs,
and the anti-bounce weight of FIG. 18, according to an
embodiment.
[0046] FIG. 22 is a perspective assembled view of the plungers, the
springs, and the anti-bounce weight of FIG. 18, according to an
embodiment.
[0047] FIG. 23 is a perspective view of a modified bolt carrier,
according to an embodiment.
[0048] FIG. 24 is an end view of the modified bolt carrier of FIG.
23, according to an embodiment.
[0049] FIG. 25 is a side view of an anvil of FIG. 23, according to
an embodiment.
[0050] FIG. 26 is an end view of the modified bolt carrier of FIG.
23 showing an impact area and a bearing area, according to an
embodiment.
[0051] FIG. 27 is an end view of the modified bolt carrier of FIG.
23 showing a plunger, according to an embodiment.
[0052] FIGS. 28A-28C are various views of the anti-bounce assembly,
according to an embodiment.
[0053] FIGS. 29A-29C are various views of the anti-bounce weight,
according to an embodiment.
[0054] FIGS. 30A-30D are various views of the plunger, according to
an embodiment.
[0055] FIGS. 31A-31C are various views of the anvil, according to
an embodiment.
[0056] FIGS. 32A-32F are various views showing a bolt carrier
modification, according to an embodiment.
[0057] FIGS. 33A and 33B are various views showing a double cut
cam, according to an embodiment.
[0058] FIG. 34A-34P are various views showing a carrier key,
according to an embodiment.
[0059] FIG. 35 is a cross-sectional side view of a portion of a
standard, i.e., contemporary, M16/M4 5.56 mm firearm with the bolt
group shown in its full forward position and full rear
position.
[0060] FIG. 36 is a cross-sectional side view of a portion of an
M16/M4 5.56 mm and 6.8 mm firearm having a bolt and barrel
extension with more robust extended locking lugs and other improved
features, with the bolt group shown in two positions, according to
an embodiment.
[0061] FIG. 37A is an enlarged cross-sectional side view showing
the locking lugs of both the standard M16/M4 5.56 mm firearm (upper
portion) and the more robust extended locking lugs of the improved
M16/M4 5.56 mm and 6.8 mm firearm (lower portion), according to an
embodiment.
[0062] FIG. 37B is an enlarged side view showing the barrel
extensions of both the standard M16/M4 5.56 mm firearm (upper
barrel extension) and the barrel extension of the improved M16/M4
5.56 mm and 6.8 mm firearm (lower barrel extension), according to
an embodiment.
[0063] FIG. 38 is an end view showing the feed ramps of a standard,
i.e., contemporary, M16/M4 5.56 mm firearm.
[0064] FIG. 39 is an end view showing the feed ramps of the M16/M4
5.56 mm and 6.8 mm firearm, according to an embodiment.
[0065] FIG. 40 shows the front sight block and gas tube of a
standard, i.e., contemporary, M4 carbine.
[0066] FIG. 41 shows a metering plug installed in a front sight
block having the gas port in the standard location and showing the
use of a thick wall gas tube, according to an embodiment.
[0067] FIG. 42 shows a metering plug installed in a front sight
block having the gas port moved to a forward location and showing
the use of a thick wall gas tube, according to an embodiment.
[0068] FIG. 43 shows a metering plug installed in a front sight
block having the gas port moved to a forward location (with an
enlarged view of the installed metering plug) and showing the use
of a thick wall gas tube, according to an embodiment.
[0069] FIG. 44 shows a metering plug installed in a front sight
block having the gas port moved to a forward location (with an
enlarged view of the uninstalled metering plug and gas tube) and
showing the use of a thick wall gas tube, according to an
embodiment.
[0070] FIG. 45 shows the anti-bounce weight having a chamfer formed
thereon to provide clearance for the hammer, according to an
embodiment.
[0071] FIG. 46 shows a cam pin having a chamfer formed thereon to
provide clearance for the cam, according to an embodiment.
[0072] Embodiments of the present invention and their advantages
are best understood by referring to the detailed description that
follows. It should be appreciated that like reference numerals are
used to identify like elements illustrated in one or more of the
figures.
DETAILED DESCRIPTION
[0073] Methods and systems are provided for enhancing the
reliability of firearms, such as firearms in the M16/M4 family of
firearms. For example, according to an embodiment a firearm can
have a bolt having a plurality of extended locking lugs that are
configured to have a shear area that is at least approximately 1.3
times that of a standard M16/M4.
[0074] A piston can be formed on the bolt and can have a plurality
of rings that are configured to cooperate with the piston to
mitigate gas leakage past the piston. Each of the rings can have a
key formed thereon and a gap formed therein such that the gap of
one ring is configured to receive at least a portion of the key of
another ring.
[0075] A bolt carrier can have the bolt movably attached thereto.
The bolt carrier can have a double cut cam. The double cut cam can
have a starting point in an unlocked position of the bolt that is
substantially the same as the standard M16 cam and can have an
unlocking cam surface that has sufficient dwell increase to delay a
start of unlocking when the bolt carrier is used in an M4 carbine
(as compared to the delay provided by the standard cam surface).
This delay can be as little as 0.00016 seconds, for example. This
delay is based on the time it takes for a 62 grain M855 bullet to
travel 5.5 inches beyond the gas port in an M16 rifle barrel at an
average velocity of 3056 feet per second. During this time the
chamber pressure significantly drops in the rifle, but not in the
carbine which has the gas port 51/2 inches closer to the chamber
that does the rifle, thus causing the gas to start to act on the
gas system 0.00016 seconds sooner in the carbine than in the rifle.
The dwell is increased so as to regain the 0.00016 second delay and
the beneficial pressure drop that is present in the rifle and not
in the standard carbine. The additional dwell needed in the cam is
0.036 inches if the carrier is at full velocity of 20 feet per
second, which is 153 times slower than the bullet since 5.5 inches
divided by 153=0.036 inches. Thus, the 0.062 inch dwell increase is
more than significant.
[0076] The 0.062 additional dwell has two advantages. It provides
the time needed to reduce chamber pressure that tends to bind the
locking lugs at the start of unlocking and it allows 0.062
additional bolt carrier bounce before safely retracting the firing
pin thus reducing the chance of a misfire from occasional carrier
bounce.
[0077] A weight can be movably disposed within the bolt carrier.
The weight can be configured to inhibit rearward and forward
bouncing of the bolt carrier. A carrier key can be attached to the
bolt carrier and can be configured to facilitate a stroke of the
bolt carrier that is approximately 0.360 inch longer than that of a
standard M16/M4. A gas tube can be configured to provide gas from a
barrel of the firearm to the piston via the carrier key. The gas
tube can have a heat radiator formed on at least a portion of the
gas tube.
[0078] A gas metering plug can have a gas metering hole configured
to meter gas from the barrel of the firearm to the bolt carrier of
the firearm. The gas metering hole can be located away from a gas
port of the firearm. A front sight block can have a rear band and a
front band for attaching the front sight block to the barrel and
can have a gas passage formed in the front band for facilitating
gas flow from the barrel to a gas tube of the firearm. These, as
well as other features, and their advantages are discussed in
detail herein.
[0079] The cooperation of these features can provide a safer, more
reliable firearm. For example, the long or extended locking lugs,
gas piston rings, and the gas tube can cooperate to make the gas
system of the firearm more robust. As a further example, the
anti-bounce weight, gas metering plug, gas passage in the forward
sight band and the double cut cam can cooperate to reduce the
cyclic rate and to better facilitate the use of the extended
locking lugs.
[0080] Methods and systems for inhibiting undesirable gas leakage
and/or heat build up in a gas operated firearm are disclosed.
According to an embodiment, a pair of rings can be configured to
interlock with respect to one another such that the rings rotate
within a groove of a piston of a gas system of a firearm. Since the
rings rotate in unison, they do not align in a manner that readily
facilitates undesirably increased gas flow past the piston. Such
rings can generally be used with both M16/M4 and HK416 types of
firearms.
[0081] According to an embodiment, a gas tube that better tolerates
the heat associated with sustained fully automatic fire of a
firearm is disclosed. The gas tube is less prone to overheating and
better accommodates thermal expansion. Thus, the firearm cycles and
fires more uniformly and is more reliable. Such a gas tube can
generally be used with M16/M4 types of firearms and generally
cannot be used with HK416 types of firearms since the HK416 types
of firearms use a substantially different gas system.
[0082] According to an embodiment, methods and systems are provided
for inhibiting undesirable forward and rearward bouncing of a bolt
carrier of a gas operated firearm, such as a fully automatic gas
operated firearm. An anti-bounce assembly, including an anti-bounce
weight, can mitigate undesirable speeding up of the cyclic rate of
a firearm due to gas port erosion and can thus reduce wear and
increase the reliability of the firearm.
[0083] According to an embodiment, a gas metering port can prevent
the cyclic rate of the firearm from increasing undesirably as the
gas port erodes. The gas port can be moved forward, from the rear
sight band to the forward sight band, to reduce pressure in the gas
system and to reduce the cyclic rate of the firearm.
[0084] According to an embodiment, stronger extended locking lugs
on the bolt and on the barrel extension can be provided to prevent
breakage thereof. The extended locking lugs are particularly useful
when the firearm is being operated with cartridges providing higher
chamber pressures. A double cut cam can provide increased dwell
such that the pressure in the chamber has time to decrease to a
point where the locking lugs (whether extended locking lugs or
standard locking lugs) can be more reliably and safely
disengaged.
[0085] Examples of embodiments of keyed gas piston rings are
discussed in detail below. Examples that are suitable for use with
the M16/M4 rifle are discussed with reference to FIGS. 1-3 and 7.
Examples that are suitable for use with the HK416 rifle are
discussed with reference to FIGS. 4-6 and 8. The gas piston of the
M16 and the M4 is an integrated part of the bolt that is slidably
disposed within a gas cylinder formed in the bolt carrier of the
firearm. The gas cylinder, i.e., the bolt carrier, moves with
respect to the gas piston.
[0086] FIG. 1 is a perspective view of a bolt 100 of a gas operated
firearm 700 (FIG. 7), according to an embodiment. The bolt 100 can
be a bolt of an M16 rifle or an M4 carbine, for example. The bolt
100 can have a piston 101 formed thereon. A groove 102 can be
formed circumferentially around the piston 101. A pair of rings 105
are shown exploded from the bolt 100. The rings 105 can comprise a
first ring 105a and a second ring 105b. The rings 105 can be
configured to be received at least partially within the groove 102
of the piston 101 of the gas operated firearm 700.
[0087] A key 108 can be formed upon each of the rings 105. The key
108 can extend generally perpendicularly with respect to a plane of
each of the rings 105. The key 108 can have a generally rectangular
cross-section when taken in either of two generally orthogonal
planes. That is the walls of the ring can generally define a
rectangle.
[0088] A gap 107 can be formed in each of the rings 105. The gap
107 of each one of the rings 105 can be configured to receive at
least a portion of the key 108 of another one of the rings 105. The
gap 107 can have a generally rectangular cross-section when taken
in either of two generally orthogonal planes. Thus, a pair of the
rings 105 can be configured to interlock with one another such that
the two rings 105 can rotate, but can only rotate substantially in
unison with respect to one another.
[0089] In an embodiment, the key 108 and the gap 107 of each of the
rings 105 can be formed such that a pair of the rings 105 are
nestable with the key 108 of each one of the rings 105 being
disposed within the gap 107 of each other one of the rings 105
while the rings 105 are substantially flush with respect to one
another. The nesting of the rings 105 interlocks the rings 105 such
that the rings 105 rotate in unison.
[0090] In an embodiment, the gaps 107 of the two rings 105 can be
diametrically opposed with respect to one another when the rings
105 are interlocked. Since the two rings 105 rotate substantially
in unison, the gaps 107 do not align in a fashion that facilitates
increased gas flow past the rings 105.
[0091] In an embodiment, the rings 105 can be formed of stainless
steel. For example, the rings 105 can be formed of 17-4 stainless
steel. Various other materials, including refractory materials such
as ceramics, are contemplated.
[0092] In an embodiment, the groove 102 can be substantially
rectangular in cross-section. In an embodiment, the rings 105 can
also be substantially rectangular in cross-section and thus can be
generally complementary in size and shape with respect to the
groove 102.
[0093] FIG. 2 is an enlarged side view of the piston 101 having the
first ring 105a completely installed thereon and having the second
ring 105b partially installed thereon, according to an embodiment.
The rings 105 can be temporarily bent or spring deformed in order
to slide over the piston 101 and into the groove 102. The key 108
of the second ring 105b is positioned to be received at least
partially within the gap 107 of the first ring 105a.
[0094] FIG. 3 is an enlarged perspective view of the piston 101
having two rings 105 installed thereon, according to an embodiment.
The two rings 105 are seated within the groove 102. The key 108 of
the second ring 105b is disposed at least partially within the gap
107 of the first ring 105a and the key 108 of the first ring 105a
is disposed at least partially within the gap 107 of the second
ring 105b.
[0095] The piston of an HK416 is disposed in a gas cylinder of a
firearm 800 (see FIG. 8) rather than in a cylinder of the bolt
carrier as discussed herein with respect to the M16/M4. FIGS. 4-6
show a system for inhibiting undesirable gas flow around the piston
of an HK416 or the like and are discussed in detail below.
[0096] FIG. 4 is a perspective view of the piston 400 of a gas
operated firearm 800 (FIG. 8), according to an embodiment. The
piston 400 can be a piston of an HK416 rifle, for example. A groove
402 can be formed circumferentially around the piston 400. A pair
of rings 405 are shown exploded from the piston 400. The rings 405
can comprise a first ring 405a and a second ring 405b. The rings
405 can be configured to be received at least partially within the
groove 402.
[0097] A key 408 can be formed upon each of the rings 405. The key
408 can extend generally perpendicularly with respect to a plane of
the rings 405. The key 408 can have a generally rectangular
cross-section when taken in either of two generally orthogonal
planes.
[0098] A gap 407 can be formed in each of the rings 405. The gap
407 of each one of the rings 405 can be configured to receive at
least a portion of the key 408 of another one of the rings 405. The
gap 407 can have a generally rectangular cross-section when taken
in either of two generally orthogonal planes. Thus, a pair of the
rings 405 can be configured to interlock with one another such that
the two rings 405 can rotate, but can only rotate substantially in
unison with respect to one another.
[0099] In an embodiment, the key 408 and the gap 407 of each ring
405 can be formed such that a pair of the rings 405 are nestable
with the key 408 of each of the rings 405 being disposed at least
partially within the gap 407 of each other of the rings 405 while
the rings 405 are substantially flush with respect to one another.
The nesting of the rings 405 interlocks the rings 405 such that the
rings 405 rotate in unison.
[0100] In an embodiment, the gaps 407 of the two rings 405 can be
diametrically opposed with respect to one another when the rings
405 are interlocked. Since the two rings 405 rotate substantially
in unison, the gaps 407 do not align in a fashion that facilitates
increased gas flow past the rings 405.
[0101] In an embodiment, the rings 405 can be formed of stainless
steel. For example, the rings 405 can be formed of 17-4 stainless
steel. Various other materials, including refractory materials such
as ceramics, are contemplated.
[0102] In an embodiment, the groove 402 can be substantially
rectangular in cross-section. In an embodiment, the rings 405 can
also be substantially rectangular in cross-section and thus can be
generally complementary in size and shape with respect to the
groove 402.
[0103] FIG. 5 is an enlarged side view of the piston 400 having the
first ring 405a partially installed thereon and having the second
ring 405b completely installed thereon, according to an embodiment.
The rings 405 can be temporarily bent or spring deformed in order
to slide over the piston 400 and into the groove 402. The key 408
of the second ring 405b is positioned to be received at least
partially within the gap 407 of the first ring 405a.
[0104] FIG. 6 is an enlarged perspective view of the piston 400
having two rings 405 installed thereon, according to an embodiment.
The two rings 405 are seated within the groove 402. The key 408 of
the second ring 405b is disposed at least partially within the gap
407 of the first ring 405a.
[0105] According to various embodiments, a device can comprise a
first ring 105a, 405a configured to be at least partially received
within a groove 102, 402 of a piston 101, 400 of a gas operated
firearm 700, 800. A second ring 105b, 405b can be configured to be
at least partially received within the groove 102, 402. The first
ring 105a, 405a and second ring 105b, 405b can be configured to
interlock with one another such that the first ring 105a, 405a and
second ring 105b, 405b rotate substantially in unison within the
groove 102, 402. Various means for effecting such interlocking are
contemplated. The use of a key 108, 408 and a gap 107, 407 as
discussed herein are by way of example only, and not by way of
limitation.
[0106] Any desired number of rings 105, 405 and any desired number
of grooves 102, 402 in the piston 101, 400 may be used. For
example, two grooves 102, 402, each containing two rings 105, 405
or three rings 105, 405 apiece, may be used. Thus, various
embodiments may comprise 2, 3, 4, 5, 6, or more rings 105, 405.
[0107] In various embodiments, the gaps 107, 407 can be partial
gaps that do not extend entirely though the rings 105, 405. For
example, the gaps 107, 407 can be sufficiently sized to receive at
least a portion of the keys 108, 408 while not forming a separation
in the rings 105, 405. Thus, the gaps 107, 407 may be depressions,
indentations, or cutouts, for example. Any desired number and
configuration of the gaps 107, 407 and the keys 108, 408 can be
used. The gaps 107, 407 and the keys 108, 408 can be generally
complementary with respect to one another. The gaps 107, 407 and
the keys 108, 408 can be non-complementary with respect to one
another.
[0108] The piston rings 105, 405 need not be received within a
groove 102, 402 of the piston 101, 400. Rather, the piston rings
105, 405 can be placed upon the piston 101, 400 and can be held in
position by any means or structure desired. The piston rings 105,
405 can cooperate with the piston 101, 400 to mitigate gas leakage
past the piston 101, 400.
[0109] According to an embodiment, the piston 400 can be configured
to fit within a gas cylinder of a firearm 800 that does not have
the piston 400 formed upon a bolt of the firearm 800, for example.
The piston 400 can be configured to fit within a gas cylinder of a
HK416 type of firearm 800.
[0110] Alternatively, the piston 101 can be formed upon a bolt 100
of the firearm 700. The gas cylinder can be formed in a bolt
carrier of the firearm 700. The piston 101, 400 can fit within a
gas cylinder of an M16/M4 type of firearm, for example.
[0111] FIG. 7 is a perspective view of the firearm 700 having the
piston 101 formed on the bolt 100, according to an embodiment. The
firearm 700 can be an M16 or an M4, for example. The firearm 700
can have one or more pairs of rings 105 disposed in one or more
grooves 102 about the piston 101 thereof to mitigate gas leakage
past the piston 101, as discussed herein.
[0112] FIG. 8 is a perspective view of a firearm 800 having the
piston 400, according to an embodiment. The firearm 800 can be an
HK416, for example. The firearm 800 can have one or more pairs of
rings 405 disposed about the piston 400 thereof to mitigate gas
leakage past the piston 400, as discussed herein.
[0113] In operation, a shooter fires the firearm 700, 800 and hot,
high pressure gas is provided by the cartridge. As shown in FIG. 7
for an M16 or M4 type of rifle, the gas travels through a front
sight (FIG. 40) to the gas tube 705, then through the gas tube 705
and a carrier key 752 to the bolt carrier 702, where the gas moves
the bolt carrier 702, and consequently the bolt 100, so as to
effect extraction of the spent cartridge and chambering of a new
cartridge. The bolt 100 is disposed within a gas cylinder 701
formed in the bolt carrier 702. As shown in FIG. 8 for an HK416
type of rifle, the gas moves the piston 400 within the gas cylinder
801 so as to move a tappet or operating rod 802 to effect
extraction of a spent cartridge and chambering of a new
cartridge.
[0114] In either instance, the use of rings 105, 405 having gaps
107, 407 and keys 108, 408 that facilitate nesting or interlocking
of the rings 105, 405 substantially mitigates undesirable gas flow
past the piston 101, 400. The nested or interlocked rings 105, 405
provide increased resistance to such gas flow by preventing the
gaps 107, 407 from aligning with respect to one another. For
example, gas can be substantially forced to follow a longer and
more contorted path under the rings 105, 405 from which the gas
reemerges to flow past the piston 101, 400. This longer and more
contorted path around four corners substantially inhibits such gas
flow and consequently inhibits gas leakage past the piston 101,
400.
[0115] Firearms 700 that have the piston 101 formed on the bolt 100
thereof can be referred to herein as M16/M4's, or M16/M4 types of
firearms, or members of an M16/M4 family of firearms. Firearms 800
that do not have the piston 400 formed on a bolt thereof can be
referred to herein as HK416's, HK416 types of firearms, or members
of an HK416 family of firearms.
[0116] Thus, according to one or more embodiments, two rings 105,
405 can be nested such that undesirable gas leakage past the piston
101, 400 is substantially inhibited. In this manner, damage to the
rings can be substantially mitigated and fouling of components of
the firearm 700, 800, such as within the receiver thereof, can be
substantially mitigated. By inhibiting gas leakage past the piston
101, 400 reliability of the firearm is substantially enhanced and
operation of the firearm is made more uniform.
[0117] Anticipating that 60-shot and 100-shot magazines may soon
replace the current standard 30-shot M16/M4 magazines, the
consequent heat problems associated with such increased capacity
(and the resulting extended rapid firing of the firearm) also need
to be addressed. The M4 gas tube 705 can soften and bend (and thus
become inoperable) in as few as four 100-shot bursts. The M16 gas
piston rings can burn out in as few as two 100-shot bursts. To
mitigate such heat problems, the keyed piston rings 104, 405 and a
heat dissipating gas tube 705 may be used, as discussed herein.
[0118] More particularly, some gas operated firearms 700 use the
gas tube 705 to deliver high pressure, very hot, gas to the piston
101 formed upon the bolt 100, as discussed herein. The M16 and the
M4 are examples of firearms 700 that deliver gas to the piston 101
via the contemporary gas tube 705. When the firearm 700 is shot
repeatedly over an extended length of time, such as during extended
fully automatic fire using a plurality of high capacity magazines,
the contemporary gas tube 705 can heat up substantially. In such
instances, the temperature of the contemporary gas tube 705 can be
excessive and thus undesirable damage to the contemporary gas tube
705 can result.
[0119] When the gas tube 705 heats up, the length and/or diameter
of the gas tube 705 can increase substantially due to thermal
expansion. Such thermal expansion can interrupt the firing cycle of
the firearm 700 and thus result in the firearm 700 becoming
inoperative. As such, it is desirable to provide methods and
systems for mitigating heat build up and for accommodating thermal
expansion of the gas tubes 705 in gas operated firearms.
[0120] As shown in FIG. 9, a heat dissipating gas tube 705 can have
enhanced heat dissipation such that during extended fully automatic
fire the gas tube 705 can remain at a sufficiently low temperature
as to not incur substantial damage. The enhanced heat accommodation
tends to allow the gas tube 705 to continue to function properly
when heated, particularly when heated by sustained fully automatic
fire. Examples of embodiments of more heat tolerant and/or heat
dissipating gas tubes 705 are discussed in detail below.
[0121] FIG. 9 shows the gas tube 705 for an M16 and/or M4 type of
firearm 700, according to an embodiment. The gas tube 705 can have
a heat dissipater formed thereon. For example, the gas tube 705 can
have screw threads 707 formed upon a substantial portion of the
length of the gas tube 705.
[0122] Other examples of heat dissipaters can include fins,
fingers, flanges, protrusions, and any other structures that tend
to increase the surface area of the gas tube 705 and thus enhance
radiation of heat from the gas tube 705. A plurality of spaced
apart annular fins can substantially encircle the gas tube 705, for
example. A plurality of longitudinal fins can extend along a length
of the gas tube 705, for example. A spiral fin can extend around a
length of the gas tube 705, for example. The fins can form a
V-notch with approximately 60 degrees between opposing walls, for
example.
[0123] The outer diameter and/or the inner diameter of the gas tube
705 can be increased to enhance the ability of the gas tube 705 to
operate under extended fully automatic fire. For example, in one
embodiment, the outer diameter of the gas tube 705 or a portion of
the gas tube 705 can be increased from the standard 0.180 inch to
approximately 0.218 inch.
[0124] According to an embodiment, the threads 707 can be a uniform
standard thread form, such as 1/4-32 UNEF (Unified National Extra
Fine) threads, for example. The threads 707 can be helical threads,
for example. Various other types of the threads 707 are
contemplated. More than one type of the threads 707 can be used.
Any desired combination of the threads 707 or types of the threads
707 can be used. In one embodiment, the threads 707 can extend
along a portion of the length of the gas tube 705. For example, the
threads 707 can extend along a portion of the gas tube 705 that is
away from ends, 721 and 722, of the gas tube 705. Thus, the ends
721 and 722 of the gas tube 705 can have no threads 707 formed
thereon. In one embodiment, the threads 707 can extend along the
entire gas tube 705.
[0125] The threads 707 need not be conventional threads. The
threads 707 need not be any type of standard threads, e.g., threads
made according to an accepted standard. The threads 707 can be
formed with a die. The threads 707 can be formed by machining. The
threads 707 can be formed by laser cutting. The threads 707 can be
formed by any desired method.
[0126] The threads 707 can be integral with the gas tube 705. The
threads 707 can be formed separately from the gas tube 705 and/or
can be attached to the tube 705. The threads 707 can be formed of
either the same material as the gas tube 705 or can be formed of a
different material with respect to the gas tube 705.
[0127] In one embodiment, the threads 707 can be solely for heat
dissipation. In one embodiment, the threads 707 can have another
use other than heat dissipation. For example, the threads 707 can
be used to mount the gas tube 705 to the firearm 700. Thus, at
least one end of the gas tube 705 can screw into a threaded opening
on the firearm 700.
[0128] The gas tube 705 can be configured to attach to a
contemporary firearm 700. For example, the gas tube 705 can have a
first bend 711 and a second bend 712 formed therein to facilitate
mounting of the gas tube 705 to a contemporary firearm 700. The
first bend 711 and the second bend 712 can align the forward end
and the rearward end of the gas tube 705 with their respective
connections to the firearm 700. A bead 725 can be formed on the
reward end of the gas tube 705 to facilitate a desired fit into the
carrier key 752 (FIGS. 10A and 11) of the firearm 700.
[0129] In one embodiment, the gas tube 705 can be formed of
stainless steel. For example, the gas tube 705 can be formed of 347
stainless steel. In one embodiment, the gas tube 705 can be formed
of a refractory material, such as a ceramic material.
[0130] The gas tube 705, and more particularly the threads 707, can
have any desired finish. For example, various textures, coatings,
and treatments that enhance heat dissipation are contemplated.
Different parts of the gas tube 705 can have different textures,
coatings, or treatments.
[0131] FIGS. 10A-10C are cross-sectional side views of portions of
the firearm 700 having the gas tube 705, according to an
embodiment. The gas tube 705 and/or the rings 105 (FIGS. 1-3) can
be provided as a kit for upgrading contemporary firearms such as
the M16 and M4. Thus, the gas tube 705 and the rings 105 can be
provided and installed together. Such upgrading can be performed in
the field, at an armory, or at a maintenance depot. The gas tube
705 and/or the rings 105 can be changed together. Either the gas
tube 705 or the rings 105 can be changed alone (without changing
the other). Thus, the gas tube 705 and the rings 105 can be changed
or used independently with respect to one another.
[0132] In operation, a shooter fires the firearm 700, 800 and hot,
high pressure gas is provided by the cartridge. For an M16 or M4
type of rifle, the gas travels through a front sight 4501 to the
gas tube 705, then through the gas tube 705 and the bolt carrier
key 752 to the bolt carrier 702, where the gas moves the bolt
carrier 702, and consequently the bolt 100, so as to effect
extraction of the spent cartridge and chambering of a new
cartridge. The bolt 100 is disposed within a gas cylinder 701
formed in the bolt carrier 702. During sustained fully automatic
fire, the gas tube 705 is exposed to a substantial quantity of hot
gases from the fired cartridges. According to an embodiment, the
threads 707 provide increase surface area for radiating this heat
so that the temperature of the gas tube 705 can be maintained
within an acceptable range.
[0133] Referring again to FIG. 9, as the gas tube 705 heats ups, it
expands both in length and diameter. According to an embodiment,
the length, Dimension M, of the gas tube 705 is sufficiently short
so as to accommodate thermal expansion of the gas tube 705 in
length without causing the firearm 700 to malfunction. Such
malfunction can occur when the length, Dimension M, of the gas tube
705 is long enough such that thermal expansion makes it too long
and the rear end thereof impacts the carrier key 752 when the
firearm cycles. Such impacting of the gas tube 705 can result in
the gas tube 705 deforming and failing.
[0134] According to an embodiment, the diameter, Dimension N, of
the gas tube 705 is sufficiently small so as to accommodate thermal
expansion of the gas tube 705 in diameter, particularly at the
carrier key 752 interface thereof, without causing the firearm 700
to malfunction. Such malfunction can occur when the diameter,
Dimension N, of the gas tube 705 is great enough such that thermal
expansion makes it too tight within the carrier key 752 and the
rear end thereof binds or freezes instead of sliding within the
carrier key 752. Such binding of the gas tube 705 can result it the
gas tube 705 deforming and failing. The rearward end of the gas
tube 705 can be a bead 725.
[0135] FIG. 11 is a cross-sectional side view of a rearward end of
the carrier key 752 of FIG. 10. The rearward end or bead 725 of the
gas tube 705 is received within the carrier key 752. When a
contemporary gas tube 705 expands in length, such as due to the
heat of sustained fully automatic fire, it may bottom out or
interfere within the carrier key 752, such that the gas tube 705
bends undesirably due to such expansion. Such bottoming out and/or
bending can inhibit uniform cycling or otherwise prevent desired
operation of the firearm 700.
[0136] According to an embodiment, the gas tube 705 can be shorter
in length, Dimension M of FIG. 9, such that additional or desirable
clearance, Dimension T of FIG. 11, is provided between the bead 725
and any portions of the carrier key 752 that the bead 725 can
bottom out or interfere with during such expansion. Dimension T is
partially defined by Dimension M, which is discussed further
herein. Dimension M is sized such that Dimension T does not
decrease to zero as the firearm 700 heats up. Dimension T can be
0.227-0.289 inch based on the maximum temperature difference
between the M16 rifle's gas tube and barrel of 2380.degree.
F..times.0.00000636 (Thermal Expansion Coefficient for
Steel).times.15 inch length (M)+0.062 tolerance.
[0137] According to an embodiment, the gas tube 705 can be shorter
in length, Dimension M and the bead 725 can have a reduced
diameter, Dimension N. Thus, undesirable interferences can be
mitigated and uniformity of cycling can be enhanced and a more
reliable firearm can be provided.
[0138] FIG. 12 is a flow chart showing a method for making a
firearm 700 having the gas tube 705, according to an embodiment.
The method can comprise cutting a piece of 1/4 OD.times.0.065 wall,
stainless steel tubing, for example, to a desired length as shown
in block 1101. For example, the tubing can be cut to a length of
approximately 9.668 inches. The tubing can be cut with a tubing
cutter or a saw, for example.
[0139] The method can further comprise forming threads 707 upon the
cut tubing, as indicated in block 1102. For example, 1/4-32 threads
can be formed upon a section of tubing having a diameter of
approximately 0.250 inch. The threads 707 can be formed with a
lathe or with a die, for example.
[0140] The method can further comprise forming a first bend 711 in
the tubing, as indicated in block 1103. A second bend 712 can be
formed in the tubing, as indicated in block 1104 to define the gas
tube 705. The first bend 711 and the second bend 712 can be formed
consecutively or simultaneously. The first bend 711 and the second
bend 712 can be formed using a fixture, jig, or tubing bend, for
example.
[0141] The gas tube 705 can be installed in a firearm 700 as
indicated in block 1105. For example, the gas tube 705 can be
installed in an M16 or an M4 type of firearm 700. The bead 725 can
be formed on the reward end of the tube 705 to facilitate a desired
fit into a gas block interface of the firearm 700. The bead 725 can
be formed at any desired point in the fabrication process. For
example, the bead 725 can be formed either before or after the
threads 707 are formed.
[0142] Referring again to FIG. 9, the gas tube 705 can comprise a
gas tube retention hole 751 that is used to pin (attach) the tube
to the front sight block 4501. According to an embodiment, the
length, Dimension M, of the gas tube 705 from the center of the gas
tube retention hole 751 to the rear end of the gas tube 705 and/or
the rear end diameter, dimension N, of the bead 725 can be
approximately the same as for a contemporary gas tube 705 for an
M16 and/or M4. For example, Dimension M can be approximately 9.600
inches for an M4 and can be approximately 14.98 inches for an M16.
For example, Dimension N can be approximately 0.180 inch. Thus, in
one or more embodiments the gas tube 705 can readily replace the
contemporary gas tube of an M16 and/or M4.
[0143] According to an embodiment, the length, Dimension M, and/or
the rear end diameter, Dimension N, of the bead 725 can be less
than for a contemporary gas tube 705 for an M16 and/or M4. For
example, Dimension M can be less than 9.570 inches for an M4 and
can be less than 14.95 inches for an M16. For example, Dimension N
can be less than 0.1792 inch diameter. Thus, the gas tube 705 can
be approximately 0.100 inch shorter and can have an outer diameter
of approximately 0.001 inch less at the rear end, i.e., the bead
725, as compared to a standard gas tube 705 for the same firearm
700. One or more embodiments can fit within the carrier key 752 of
an M16 and/or M4 and can readily replace contemporary gas tubes
705. The shorter length, Dimension M, and the smaller outer
diameter, Dimension N, can better accommodate thermal expansion,
such as can be caused by using larger capacity magazines. Thus, the
gas tube 705 can have further enhanced heat resistance.
[0144] According to an embodiment, the outer diameter, Dimension Q,
of a portion of the gas tube 705 at the rear end thereof can be
approximately 0.171 inch. The diameter, Dimension P, of the gas
tube 705 can be 0.186 inch.
[0145] The dimensions of the gas tube 705, as well as the
configuration thereof, including any bends therein, can be whatever
is necessary to fit a particular firearm. More or less than two
bends can be used. Thus, the gas tube 705 can have any desired
shape and configuration.
[0146] One or more embodiments can provide a replacement for
contemporary gas tubes 705. Such embodiments are less prone to
overheating and less likely to malfunction due to heat induced
weakness and/or heat induced thermal expansion, particularly during
sustained fully automatic fire of the firearm 700. Thus, the
firearm 700 can cycle and fire more uniformly and can be
substantially more reliable.
[0147] One or more embodiments can provide a replacement for
contemporary gas tubes 705 that can withstand the heat of firing at
least as well as other components of the firearm 700. Thus, a
failure or problem with the gas tube will be substantially less
likely to be the cause of a malfunction of the firearm 700.
[0148] An often neglected problem in gas operated firearms is gas
port erosion. Gas port erosion causes the gas port to become
larger, which allows more gas to be used and thus gradually speeds
up the gun cycle. Speeding up the gun cycle can cause feed jams,
failures to extract, and carrier bounce misfires. It can also
increase wear on the firearm and reduce accuracy during use of the
firearm.
[0149] The M4 carbine has more trouble with gas port erosion than
the M16 rifle, even though both of these firearms use the same bolt
carrier group. The M4's gas port location is closer to the chamber,
where gas port erosion is more aggressive. Because of gas port
erosion, the M4's unlocking cam can begin to unlock too early in
the firing cycle and thus can cause a bolt with standard locking
lugs to break at the lugs or cam pin hole. This typically doe not
occur in the M16 rifle and typically does not occur in new M4s. It
generally only occurs in M4s that have fired enough to
substantially erode the gas port. In addition to reliability
problems, the resulting high rate of fire makes the gun less
controllable on full auto, wastes ammunition, and intensifies heat
problems.
[0150] Contemporary M16/M4 firearms have a gas tube 705 with a plug
706 (FIG. 40) at the front end of the gas tube 705. However, the
plug 706 of a contemporary M16/M4 firearm does not substantially
restrict gas flow. Contemporary M16/M4 firearms rely upon the gas
port 1003 formed in the barrel to perform a gas metering function.
The gas port 1003 is subject to erosion as discussed herein and
thus suffers from substantial disadvantages with regard to this
metering function.
[0151] More particularly, the M16 and M4 use the gas port 1003
diameter as the means to control the amount of gas flow. However,
the forward corner of the gas port 1003 intersection with barrel
bore is eroded from its original sharp corner into an enlarging
triangle by the scrubbing of each passing bullet and the
bombardment of propellant grains. This erosion of the gas port 1003
increases its size and thus undesirably allows the gas flow
therethrough to increase over time. As the gas flow increases, the
gun cycle speeds up, undesirably resulting in feed jams, extraction
failures, and/or carrier bounce. Misfires begin and grow worse over
time until the gun cripples itself from excessively worn and/or
broken parts.
[0152] As shown in FIG. 10B, a gas metering plug 1001 can be
installed in the front end of the gas tube 705 to mitigate the
undesirable effects of gas port erosion. The gas metering plug 1001
can have a gas metering hole 1002 that the gas from the barrel must
flow through before entering the gas tube 705. According to an
embodiment, the gas metering hole 1002 is out of reach of bullet
scrubbing and the impact of propellant grains. The gas metering
plug 1001 can be made of a heat resistant material, so that it
remains substantially unchanged by any amount of firing.
[0153] According to an embodiment, the gas metering hole 1002 is
always smaller, e.g., has a smaller diameter, than the hole of the
gas port 1003 (such that the gas metering hole 1002 always performs
a gas metering function). Thus, although the gas port 1003
continues to erode so that the gas flow that reaches the gas
metering hole 1002 continues to increase in pressure, the gas
metering hole 1002 meters the gas and thus mitigates the
undesirable effects of gas port erosion so as to the extend the
useful life of the gun.
[0154] As discussed herein, the M16 service rifle and the M4
carbine have a variety of reliability shortcomings. Undesirable
forward and rearward bouncing of the bolt carrier 702 is one such
shortcoming. Insufficient dwell and early unlocking of the bolt 100
are another shortcoming. Methods and systems disclosed herein can
be used in combination with one another to mitigate shortcomings of
the M16/M4. For example, a drop in replacement kit can be provided
to address this and others of these shortcomings.
[0155] FIGS. 13 and 14 show a bolt carrier 702 having a longer
dwell, double cut cam 1301 (FIG. 33B) and an anti-bounce assembly
1305, according to an embodiment. The double cut cam 1301 is
particularly useful when applied to the M4 due to the insufficient
dwell of the M4. To prevent broken bolts, the double cut cam 1301
can have a 0.062 longer dwell as compared to the standard M4 cam.
Thus, the bolt 100 can be delayed substantially before the
unlocking cam surface 3301 (FIG. 33B) begins to rotate the bolt 100
to its unlocked position. This longer dwell at least partially
compensates for the time differences between the M16 unlocking
start and the early start of the M4 due to its rearward gas port
location, as discussed herein. The force on the extended bolt
locking lugs 3601 (FIG. 1) that would cause the extended bolt
locking lugs 3601 to bind is thus reduced to the same resistance as
in the M16 rifle, so that the cause of broken bolts is
substantially eliminated.
[0156] A single cut cam of the same new length with 0.062 longer
dwell would have the same timing advantage, but the double cut has
two additional advantages. The helix portion 3102 (FIG. 33B) of the
cam has wider clearance for dust and dirt. Although the unlocking
cam surface 3301 has 0.062 longer time dwell, the cam pin and bolt
head location on the locking side have the same starting location
as the standard cam so that the bolt head overtravels beyond the
bolt holdopen device by the same amount giving the holdopen enough
time to rise into position.
[0157] According to an embodiment, the adverse effects of gas port
erosion and higher rate of fire (excessive cycle speed) can be
substantially mitigated by three compatible but separate features.
First, a gas metering plug 1001 can be installed in the end of the
gas tube 705 and the gas metering plug 1001 can have a gas metering
hole 1002 that the gas must flow through.
[0158] Second, undesirable bounce of the bolt carrier 702 can be
substantially mitigated. It is not surprising that gas port erosion
speeds up the firearm cycle, because the bolt group (comprising the
bolt 100 and related components) is thrown more vigorously to the
rear. However, it is important to also appreciate that the forward
cycle of the bolt group also undesirably speeds up. Faster forward
movement is caused by bouncing of the bolt carrier 702 as the
buffer 3503 (FIG. 35) and the bolt carrier 702 impact the rear wall
3577 of the firearm 700. The buffer 3503 doesn't bounce, but bolt
carrier 702 does bounce. If rear bouncing of the bolt carrier 702
can be eliminated, then approximately half the rate of fire gain
can be desirably eliminated.
[0159] For example, assume that the cyclic rate of fire of a new M4
is 800 shots per minute and that the firearm has fired enough
rounds to erode the gas port sufficiently to speed up the cyclic
rate to 1000 shots per minute. This represents an increase of 200
shots per minute in the cyclic rate. If that increase were cut in
half, the gain would only be 100 shots per minute. Thus, the
firearm would have a cyclic rate of 900 shots per minute instead of
1000 shots per minute and the useful life of the firearm would be
substantially extended.
[0160] When the bolt group begins to move forward slowly, it starts
to push the top cartridge in the magazine forward, so that the top
cartridge enters the feed ramp at a slow speed and is smoothly
cammed upward into the chamber opening. By way of contrast, if the
bolt group bounces forward at high speed, then the bullet point
hits the feed ramp (which is 7.degree. steeper in the M4 than in
the M16) at high speed. The bullet tends to bounce higher as the
cyclic rate increase. When the cyclic rate increases sufficiently,
the bullet will miss the chamber opening and jams the firearm 700.
Although this commonly occurs with contemporary 30-shot magazines,
high capacity magazine provided by SureFire, LLC of Fountain
Valley, Calif. are designed to feed reliably at a very wide range
of cyclic rates.
[0161] Referring to FIGS. 13-33A, a combination rate reducer and
anti-bounce assembly, referred to herein as anti-bounce assembly
1305, can be mounted in the rear tubular section 1350 that is
common to both the M16 and M4 bolt carrier 702, according to an
embodiment. The only modification needed to be made to the bolt
carrier 702 is a vertical cut or slot 1352 formed through the left
side wall of the bolt carrier 702 as shown in FIG. 18.
[0162] As shown in FIGS. 15-17, the anti-bounce assembly 1305 can
comprise a steel cylinder or anti-bounce weight 1400 having a first
cavity 1511 and second cavity 1512 formed therein. A first spring
1521 can be disposed in the first cavity 1511 upon a first plunger
1531 and a second spring 1522 can be disposed in the second cavity
1512 upon a second plunger 1532. The first plunger 1531 and the
second plunger 1532 can be substantially hollow. A spring pin 1355
can interconnect the first plunger 1531 and the second plunger 1532
and can pass through an opening 1862 in an anvil 1351.
[0163] The anti-bounce weight 1400 can be free to slide within the
bolt carrier 702 and can be biased centrally by the first spring
1521 and the second spring 1522, which can bear upon the anvil
1351. The anvil 1351 can be fixed with respect to the bolt carrier
702. The anvil 1351 can be received within the slot 1352 formed in
the bolt carrier 702. The first cavity 1511 and the second cavity
1512 can have a first blocking shoulder 1541 and a second blocking
shoulder 1542 that prevent the first plunger 1531 and the second
plunger 1532 from moving beyond their centering positions, so that
when inertia moves the anti-bounce weight 1400 beyond center, then
one plunger 1531, 1532 compresses its associated spring 1521, 1522
so as to provide a force that tends to return the anti-bounce
weight 1400 to center while the other plunger 1532, 1531 and spring
1522, 1521 are blocked from acting upon the anti-bounce weight
1400.
[0164] As shown in FIG. 15, the anti-bounce weight 1400 is in a
zero or non-impact position. This is the position of the
anti-bounce weight 1400 prior to firing the firearm 700 and after
the firearm 700 has completed a firing cycle.
[0165] As shown in FIG. 16, the anti-bounce weight 1400 is in a
rearward impact. This is the position of the anti-bounce weight
1400 after firing the firearm 700 once the bolt carrier 702 has
moved rearwardly sufficiently to cause the anti-bounce weight 1400
contact the anvil 1351. The anvil 1351 has traveled rearward with
the bolt carrier 702 to cause the impact.
[0166] As shown in FIG. 17, the anti-bounce weight 1400 is in a
forward impact. This is the position of the anti-bounce weight 1400
after firing the firearm 700 once the bolt carrier 702 has ceased
moving rearwardly to cause the anti-bounce weight 1400 to again
contact the anvil 1351 on the opposite side of the anvil 1351 with
respect to that shown in FIG. 16. The anvil 1351 has traveled
forward with the bolt carrier 702 to cause the impact.
[0167] As shown in FIG. 18, a central cavity 1801 can be formed
between the two cavities 1511 and 1512 of the anti-bounce weight.
The central cavity 1801 can define a continuous passage between the
two cavities 1501 and 1502. The anvil 1351 is disposed within the
central cavity 1801. The anvil 1351 moves within the central cavity
1801 as the bolt carrier 702 travels rearward and forward.
[0168] The two plungers 1531 and 1532 can extend through
corresponding openings 1821 and 1822 into the central cavity 1801.
The anti-bounce assembly 1305 can be secured within the bolt
carrier 702 by inserting the anti-bounce assembly 1305 into the
tubular section 1350 of the bolt carrier 702, then placing the
anvil 1351 into the slot 1352 in the bolt carrier 702 and on into
the central cavity 1801, and then inserting the spring pin 1355
through the hollow plungers 1531, 1532 and through the hole 1862 in
the anvil 1351.
[0169] The anti-bounce weight 1400 can slide forward and rearward
within the tubular portion 1350 of the bolt carrier 702. The
springs 1521 and 1522 can tend to center the anti-bounce weight
1400. The dimensions of the central cavity 1801 can allow the
anti-bounce weight 1400 to move fore and aft approximately 0.10
inches, for example, before the anti-bounce weight 1400 impacts the
anvil 1351. Such motion is resisted in either direction by the
force of each spring 1521, 1522 and by the fact that each plunger
1531, 1532 has a travel limiting stop or blocking shoulder 1541
(FIG. 19) formed thereon. Thus, when inertia drives the anti-bounce
weight 1400 forward to strike the anvil 1351, then only the
rearward spring 1522 is compressed (as shown in FIG. 17), while the
forward spring 1521 and plunger 1531 move away from the anvil 1351
and the opposite occurs when the weight 1400 move rearward (as
shown in FIG. 16). In this way, the springs 1521 and 1522 are
preloaded and biased to hold the anti-bounce weight 1400 in mid
position, e.g., approximately centered (as shown in FIG. 15) within
its limits of travel.
[0170] When the bolt carrier 702 impacts forward and tends to
bounce rearward, the anti-bounce weight 1400 impacts forward again
(as shown in FIG. 17) and vice-versa (as shown in FIG. 16). Thus,
the anti-bounce weight 1400 partially defines an anti-bounce device
in both directions, not just in the forward direction. Since the
anti-bounce assembly 1305 mitigates rearward bounce, it is also a
rate reducer (it tends to reduce the cyclic rate of a firearm).
According to one or more embodiments, the anti-bounce assembly 1305
can be a semi-permanent installation. That is, the anti-bounce
assembly 1305 can be removed by driving the spring pin 1355 into
the forward plunger 1532 or the anti-bounce assembly 1305 can
remain in place since standard disassembly of the firing pin, cam
pin, and bolt can be performed with the device installed.
[0171] FIGS. 19-23 show further detail regarding the construction
of the anti-bounce assembly 1305. The anvil 1351 is removed from
FIGS. 19-22 for clarity. The anvil 1351 is shown in FIG. 23
positioned for insertion into slot 1352 formed in the bolt carrier
702. The anvil 1351 both maintains desired positioning of the
anti-bounce weight 1400 within the bolt carrier 702 and provides a
stop for defining the limits of motion of the anti-bounce weight
1400. The anti-bounce weight 1400 strikes the anvil 1351 as the
anti-bounce weight 1400 functions to mitigate undesirable bouncing
of the bolt carrier 702.
[0172] FIG. 24 shows a cross section of the modified bolt carrier
702. The cross section is taken where the slot 1352 is formed to
receive the anvil 1351.
[0173] FIG. 25 and FIGS. 31A-31C show the anvil 1351. The anvil
1351 can be generally crescent shaped with a hole 1862 proximate
the middle thereof. The anvil can have a curved outer surface 1362
which can conform generally to the curvature of the bolt carrier
702 within which the anvil 1351 is disposed. The anvil 1351 can
have any desired shape. The hole 1862 receives the spring pin
1355.
[0174] FIG. 26 shows an impact area 1370 where the anti-bounce
weight 1400 strikes the bolt carrier 702 curing cycling of the
firearm 700. A bearing surface 1371 of the bolt carrier 702 where
the anvil contacts the bolt carrier 702 when the anvil is installed
in the bolt carrier 702 is also shown.
[0175] FIG. 27 shows a cross section of the bolt carrier 1350 with
the anvil 1351 installed in the slot 1352. The spring pin 1355 is
installed in the plungers 1531 and 1532.
[0176] FIGS. 28A and 28B show the anti-bounce assembly 1305 in
cross section. The anti-bounce weight 1400, the plungers 1531 and
1532, the springs 1521 and 1522, the anvil 1351, and the spring pin
1355 are installed in the bolt carrier 702.
[0177] FIGS. 29A-29C show the cavities 1511 and 1512 of the
anti-bounce weight 1400 where the plungers 1531 and 1532 are
disposed. The plungers 1531 and 1532 are removed for clarity.
[0178] FIGS. 30A-30D show a plunger 1531, 1532. The plunger 1531,
1532 comprises a generally cylindrical shaft or spring guide 1535
upon which the spring 1521, 1522 is compressibly disposed and a
shoulder 1536 against which the spring 1531, 1532 bears. A limiting
stop 1541 partially defines the limit of travel of the anti-bounce
weight 1400, as discussed herein. FIG. 31A-31C show the anvil 1351.
FIG. 31B is a side view of the anvil 1351. FIG. 31C shows a
cross-section of the anvil through the hole 1862.
[0179] FIGS. 32A-32F are various views showing a modification of
the bolt carrier 702, according to an embodiment. The slot 1352 can
be cut into a standard bolt carrier 702 to receive the anvil 1351.
The slot 1352 can be milled into the bolt carrier 702, for example.
The anti-bounce assembly 1305 can thus be easily added to a
standard bolt carrier 702.
[0180] FIGS. 33A-33B show a longer dwell, double cut cam 1301,
according to an embodiment. Exemplary dimensions for the double cut
cam 1301 are provided. Double cutting the cam 1301 delays unlocking
of the bolt 100 and provides other advantages, as discussed
herein.
[0181] The longer dwell of the double cut cam 1301 allows the
chamber pressure to drop more that is allowed by the single cut cam
of a standard M4 carbine, so as to better assure that the pressure
is low enough to safely and reliably disengage the extended bolt
locking lugs 3601. The anti-bounce weight makes the firearm 700
more controllable and reduces the cyclic rate as compared to a
standard M16/M4.
[0182] Double cutting the cam 1301 extends the bolt head 3530 (FIG.
36) approximately 0.062 inch forward. This extended amount adds
0.130 inch of additional length to the extended bolt locking lugs
3601 for an additional total extension of approximately 0.192 inch
out of the front of the bolt carrier 702 compared to standard
M16/M4. In the standard M16/M4 firearm 700 (FIG. 35), such double
cutting of the cam 1301 and such extended bolt locking lugs 3601
eliminates the 0.188 nominal over travel of the bolt head 3530
beyond the bolt catch 3632 and thus blocks proper functioning of
the bolt catch 3632 (FIG. 35).
[0183] A bolt group 3650 can include the bolt 3610, the bolt
carrier 702, and the carrier key 752, among other items. To
facilitate proper functioning of the bolt catch 3632 and to improve
on such functioning without undesirably mitigating the benefits of
the more robust extended bolt locking lugs 3601, as well as the
delayed unlocking that results from the extended bolt locking lugs
3601 and the double cut cam 1301, a shortened buffer 3503 and
modified carrier key 752 allow the bolt group 3650 to travel
approximately an additional 0.360 inch rearward.
[0184] With particular reference to FIG. 33B, examples of dimension
are provided for the double cut cam 1301. These dimensions provided
the longer dwell. Other dimensions can similarly provide a longer
dwell.
[0185] The helix portion 3102 of the double cut cam 1301 can
provide wider clearance to better accommodate soiling, e.g., dust
and dirt. The unlocking cam surface 3301 can have 0.062 longer time
dwell. The cam pin and bolt head location (not shown) on the
locking side can have the same starting location as the standard
cam so that the bolt head overtravels beyond the bolt holdopen
device by the same amount giving the bolt holdopen device
sufficient time to rise into position.
[0186] Referring now to FIGS. 34A-34P, the carrier key 752 can have
a reduced profile that avoids interference, e.g., impacting of the
carrier key 752 with a lower receiver's rear band 3640 (FIG. 36).
The reduced profile of the carrier key 752 can be necessitated by
the longer extended bolt lugs 3601.
[0187] The carrier key 752 can have a single bolt hole 3421, as
opposed to a contemporary carrier key which has two bolt holes. It
has been found that the use of a single mounting bolt is sufficient
for securely attaching the carrier key 752 to the bolt carrier 702
and the use of a single mounting bolt facilitates increase travel
of the bolt carrier 702 due to the use of the longer extended bolt
locking lugs 3601, as discussed herein. The use of a single
mounting bolt facilitates additional clearance to define low
profile 3422 to prevent the rear portion of the carrier key 752
from contacting the receiver's rear band 3640 when the firearm 700
cycles. Further, the carrier key 752 can be mounted in a deeper cut
channel of the bolt carrier 702.
[0188] The use of a 0.500 inch shorter carrier key 752, a shortened
buffer 3503 (FIG. 36) can increase the bolt carrier 702 allowable
travel by approximately 13% and can reduce the rate of fire of the
firearm 700 to about 80% of what it otherwise is. Except for the
design of the key 752, the only change to the carrier 702 can be
that two number 8 screw holes are replaced with a single 10-32
screw hole.
[0189] Although this alone does not necessarily reduce parts wear,
it can increase full auto controllability and hit probability,
conserve ammunition and reduce heat buildup. Thus, operation and
reliability can be enhanced. The use of such a carrier key 752 can
comply and work normally without the shortened buffer 3503 (FIG.
36). It can therefore be offered to create the option to use a
shortened buffer and spring stack for a reduced rate of fire.
[0190] The carrier key 752 is shown during various manufacturing
steps thereof. More particularly, FIGS. 34A-34C show a block shape
of the carrier key 752. FIGS. 34D-34G show the carrier key 752
after a drill and ream processes. FIGS. 34H-34J show the carrier
key 752 after lath turning. FIGS. 34K-34N show the carrier key 752
after form cutting. FIGS. 340-34P show the profile of the finished
carrier key 752.
[0191] According to an embodiment, more robust extended bolt
locking lugs 3601 can be formed upon the bolt and more robust
extended barrel locking lugs 4410 can be formed upon the barrel
extension 3612, as discussed herein. The use of more robust
extended bolt locking lugs 3601 and more robust extended barrel
locking lugs 4410 mitigates failure thereof. Such failure of the
extended bolt locking lugs 3601 and the extended barrel locking
lugs 4410 can result in damage to the firearm 700, as well as
possibly lose of life, particularly in police use and battlefield
operations.
[0192] The limit of increased bolt group travel is reached at
approximately 0.156 inch before the bottom front chamfer of the
bolt carrier 702 over travels the notch 3632 in semi auto hammers.
The approximate 2.85 inch length of the buffer 3503 prevents this
over travel.
[0193] An approximately 0.188 inch standard over travel of the bolt
head 3530 with respect to the bolt catch 3632 provides sufficient
time to operate the bolt catch 3632, unless the cyclic rate of the
firearm 700 increases. The cyclic rate can increase due to gas port
erosion or the use of a sound suppressor. According to an
embodiment, the over travel is increased to approximately 0.355
inch for greater reliability.
[0194] The additional approximately 0.360 inch bolt group travel
reduces the rate of fire (cyclic rate) and increases the
reliability of the firearm 700. The anti-bounce assembly, gas
metering tube, and improved gas tube discussed herein also increase
the reliability of the firearm 700.
[0195] FIG. 35 is a cross-sectional side view of a portion of a
standard M16/M4 5.56 mm firearm 7000. The bolt locking lugs 3501,
the carrier key 752, the buffer 3503, the cam 1301, the ramps 3505,
the bolt 100, the barrel extension 3612, and the bolt carrier 702
are standard (contemporary). That is, the firearm 700 has not been
modified according an embodiment. The carrier key 752 has two
screws 3571 that provide attachment of the carrier key 752 to the
bolt carrier 702. FIG. 35 is provided to better facilitate a
contrast with respect to embodiments described herein.
[0196] FIG. 36 is a cross-sectional side view of a portion of an
M16/M4 5.56 mm and 6.8 mm firearm 700, according to an embodiment.
FIG. 36 shows the use of the buffer 3503 that is 0.360 inch shorter
than standard, the use of the carrier key 752 that is mounted via a
single screw 3671 in a deeper cut carrier channel to facilitate the
use of the anti-bounce assembly 1305.
[0197] The bolt carriers 702 in both FIG. 35 and FIG. 36 are shown
in both the forwardmost (locked) and rearwardmost positions. These
are the two extremes of travel for the bolt carrier 702.
[0198] The extended bolt locking lugs 3601, carrier key 752, buffer
3503, cam 1301, and ramps 3505 have been modified to provide more
robust operation of the firearm 700. More particularly, a bolt 3610
having more robust extended bolt locking lugs 3601 and a barrel
extension 3512 having more robust extended barrel locking lugs
4410. For example, the extended bolt locking lugs 3601 can be
lengthened so as to provide at least approximately 1.3 times (such
as approximately 1.35 times) the shear area as compared to those of
the standard M16/M4 firearm (FIG. 35).
[0199] FIG. 37 is an enlarged cross-sectional side view showing the
unmodified or standard bolt locking lugs 3501 of the standard
M16/M4 5.56 mm firearm in the upper portion of the figure and
showing the more robust extended bolt locking lugs 3601 of the
M16/M4 5.56 mm and 6.8 mm firearm, according to an embodiment, in
the lower portion of the figure. The standard bolt locking lugs
3501 and the more robust extended bolt locking lugs 3601 are shown
engaged with the complementary standard barrel extension locking
lugs 3511 and the more robust extended barrel locking lugs 4410,
respectively.
[0200] As shown in FIGS. 37A and 37B, a flange 3613 can be formed
upon the barrel extension 3612 such that the flange 3613 is
approximately 0.130 inch from a forward end of the barrel extension
3612. Thus, instead of the flange 3613 of an embodiment being at
the forward end of the barrel extension 3612, as is the flange 3513
of a standard M16, the flange 3613 is rearward of the forward end
of the barrel extension 3612 by an amount approximately equal to
the added length of the bolt lugs 3601 and the barrel extension
lugs 4410. In this manner, the threaded length of the barrel is
maintained and the strength of the barrel is not compromised. This
is done without requiring any change to the receiver body, the
barrel nut, the fore end of the firearm, or the position of the gas
block.
[0201] FIG. 38 shows the feed ramps 3505 and standard barrel
locking lugs 3511 of the standard M16/M4 5.56 mm firearm 700. The
feed ramps 3505 are formed in the barrel extension 3512. The
narrower, steeper feed ramps 3505 decrease the reliability of the
firearm 700 by allowing bullets to bounce high and occasionally
miss the chamber, thus causing a feed jam.
[0202] FIG. 39 is an end view showing the feed ramps 3605 and
extended barrel locking lugs 4410 for an M16/M4 5.56 mm and 6.8 mm
firearm 700, according to an embodiment. The feed ramps 3605 are
formed in the barrel extension 3612. The stronger extended barrel
locking lugs 4410 and the wider and longer (less steep) feed ramps
3605 facilitate more reliable operation of the firearm 700. The
wider and longer feed ramps 3505 provide a better feed angle for
the firearm 700 and are thus less likely to cause a jam. Examples
of parameters used to define the wider and longer feed ramps 3505
are shown.
[0203] Referring now to FIGS. 40-44, a rearwardly positioned gas
port 1003 of a contemporary M16/M4 type of firearm 700 can be moved
forward, away from the receiver, so as to increase the time between
firing a cartridge and cycling the bolt of the firearm and so as to
reduce the pressure used to cycle the firearm 700. The cyclic rate
of the firearm 700 can be reduced and stress on components of the
firearm 700 can be reduced. In this manner the reliability of the
firearm 700 can be substantially enhanced, as discussed herein.
[0204] FIGS. 40 and 41 show the rearwardly positioned gas port 1003
as it is positioned in a contemporary M4 firearm. FIG. 41
additionally shows the use of the gas metering plug 1001, according
to an embodiment. FIGS. 42-44 show the gas port 1003 moved forward
as well as showing the use of the gas metering plug 1001, according
to an embodiment.
[0205] With particular reference to FIG. 40, the front sight block
(also know as a gas block or forging) 4501 and gas tube 705 of a
contemporary firearm 700, i.e., an M4 carbine, are shown. Firearms
of the M16/M4 family are constructed such that the rearwardly
positioned gas port 1003 of the barrel 4507 is located proximate
the rear band 4504 of the sight block 4501. Gas from the barrel
4507 passes through the rearwardly positioned gas port 1003 and
through a gas passage 4503 in the rear band 4504 to reach the gas
tube 705. The gas port 1003 performs the gas metering function and
is subject to wear, thus causing problems as discussed herein.
[0206] With particular reference to FIG. 41, the gas port 1003 is
again located proximate the rear band 4504 of the sight block 4501.
The gas metering plug 1001 has been added to the gas tube 705 to
regulate the flow of gas from the gas port 1003 to the gas cylinder
701 (FIG. 7), to compensate for wear of the gas port 1003 as
discussed herein. Thus, the gas metering plug 1001 can be installed
in a firearm 700 that has the gas port 1003 in the standard
location, i.e., proximate the rear band 4504.
[0207] A thick wall gas tube 705 can additionally be used,
according to an embodiment. The gas metering plug 1001 can be
disposed within the front sight block 4501, such as within that
portion of the thick wall gas tube 705 that is received within the
front sight block 4501. The gas metering plug 1001 can be installed
anywhere along the path of the gas from the gas port 1003 to the
gas cylinder 701 as long as the gas metering plug 1001 is installed
sufficiently far away from the gas port 1003 so as to not be
substantially subject to wear cause by the hot gases and burning
propellant.
[0208] With particular reference to FIGS. 42-44, a gas passage 4702
can be formed in the front band 4505 of the sight block 4501.
Moving the gas passage 4702 to the front band 4505 allows the gas
port 1003 to be moved forward in the barrel 4507, thus delaying the
time at which the gas acts upon the piston 101 (FIG. 1) and
decreasing the pressure of the gas. In this manner, the cyclic rate
of the firearm 700 can be reduced and undesirable forces acting
upon components of the firearm 700 can be reduced.
[0209] The gas port 1003 can be re-located to this more forward
position without moving or changing the shape of the front sight
block 4501 or the rear 4504 and front 4505 bands, which surround
the barrel 4507 to attach the front sight block 4501 to the barrel
4507. The gas passage 4702 is drilled in the front band 4505
instead of in the rear band 4504. Clearance 4810 can be provided in
the lower portion of the front band 4505 either prior to such
drilling or by the drilling process itself so as to facilitate such
drilling.
[0210] The rear band 4504 and the front band 4505 can be formed
integrally with the front sight block 4501 (as a single forging or
casting, for example). Alternatively, the rear band 4504 and the
front band 4505 can be formed separately with respect to the front
sight block 4501.
[0211] The gas port 1003 (FIG. 40) of a contemporary firearm was
originally located in the rear band 4504 when the front sight block
4501 was designed for the longer barrel of the M16 rifle. Then, the
same front sight block 4501 and the rearwardly positioned gas port
1003 configuration was used for the 51/2 inch shorter carbine
barrel. In the carbine, the front sight block 4501 was moved
rearward 51/2 inches (with respect to the rifle) to maintain the
standard distance from the bayonet lug to the muzzle. The
rearwardly positioned gas port 1003 was also moved rearward 51/2
inches.
[0212] The distance from bullet start (firing) to the gas port
determines the available pressure and the distance from gas port to
the muzzle determines the time that pressure is available, thus the
ratio between the two distances determines the impulse (force
multiplied by time) of the gas system for the gun. The ratio for an
181/2 inch bullet travel length of the rifle barrel is 63/37 (63%
from the bullet start to the gas port and 37% from the gas port to
the muzzle). The ratio for the 13 inch bullet travel length of the
carbine barrel is 47/53. Since the ratio used for the rifle barrel
proved to be reliable over decades of service, this reliability
suggests that the distance from bullet start to the gas port used
on the carbine barrel is two inches shorter than necessary to
maintain the same ratio as the rifle. It thus indicates that the
gas port is much closer to the firing chamber (bullet start
position) in contemporary M16/M4 firearms than it needs to be.
[0213] Placing the gas port 1003 closer to the chamber causes the
gas port 1003 (FIG. 46) to be subjected to higher pressure and
temperature than necessary. This is because the closer the gas port
1003 is to the chamber, the higher the temperature and pressure to
which the gas port 1003 is exposed. Higher temperatures and
pressures undesirably cause more aggressive gas port erosion.
Additionally, as the carbine's gas system starts unlocking the bolt
while there is higher pressure in the chamber (compared to the
rifle), the bolt's cam pin hole and standard bolt locking lugs 3501
are undesirably subjected to more stress, which can cause them wear
prematurely, bind, and ultimately fail.
[0214] Without changing the external dimensions of the front sight
block 4501 (these dimensions need to remain the same to accommodate
the bayonet, tripod, barrel launched grenade and separate grenade
launcher) a full two inch correction isn't feasible. However, it is
feasible to reposition the gas port 1.23 inches further forward as
discussed herein, thus gaining substantial benefit. Thus, by moving
the barrel's gas port and the gas block's passageway hole from the
rear band 1.23 inches forward into the front band 4505, problems
associated with contemporary firearms can be substantially
mitigated.
[0215] A bore 4712 can be formed in the front sight block 4501 for
receiving the gas tube 705. The bore 4712 can extend completely
through the front sight block 4501.
[0216] As best shown in FIGS. 43 and 44, the gas metering plug 1001
can comprise a bore or gas metering hole 1002 and an inlet 4804.
The inlet 4804 and/or gas metering hole 1002 are sized and
configured to provide the desire gas metering function. That is,
either the inlet 4804, gas metering hole 1002, or both are
configured to allow a desired amount of gas to flow from the gas
port 1003 to the gas tube 705. The inlet 4804 and/or gas metering
hole 1002 can define a fixed, calibrated orifice for determining
the amount of gas flow through the gas metering plug 1001. Thus,
the amount of gas used to cycle the firearm can be better
controlled, e.g., can be fine tuned.
[0217] An opening 4803 can be formed in the gas tube 4791 to
facilitate gas flow from the gas passage 4702 to the gas metering
plug 1001. A hole 4802 can be provided through the gas metering
plug 1001 and/or the gas tube 705 to facilitate attachment, e.g.,
pinning, of the gas tube 705 and/or the gas metering plug 1001 to
the front sight block 4501.
[0218] FIG. 45 shows the anti-bounce weight 1400 having a chamfer
5101 formed thereon to provide clearance for the hammer of the
firearm 700, according to an embodiment. According to other
embodiments, the chamfer 5101 can be omitted, such a when the
anti-bounce weight 1400 will not interferer with desired movement
of the hammer.
[0219] FIG. 46 shows a cam pin 5200 having a chamfer 5201 formed
thereon to provide clearance for the cam 1301, according to an
embodiment. The chamfer 5201 can extend around the periphery of the
end of the camp pin 5200 that extends into the cam 1301. The
chamfer 5201 can be omitted in embodiments where tolerances
permit.
[0220] One or more embodiments can be used in various different gas
operated rifles, carbines, pistols, and the like. Although
embodiments are discussed herein with respect to the M16/M4 and
HK416, such discussion is by way of illustration only and not by
way of limitation. Various embodiments can be used with various gas
operated firearms, including rifles, carbines, and pistols.
[0221] One or more of the embodiments described herein can be used
to modify standard M16/M4 firearms. The embodiments can mitigate
problems with the M16/M4 firearms and/or can enhance the
performance of M16/M4 firearms. The embodiments tend to required
little change to the production gun or its production tooling, so
that an M16/M4 manufacturer can, with comparatively little expense
and effort, convert the fifty-two year old design of the M16 into a
higher performance product. This higher performance product can
reliably fire the SureFire 60 and 100 round high capacity
magazines. These high capacity magazines provide one to three times
the firepower of the present twenty shot standard magazines. Thus,
such high capacity magazines can be used the without burning out
the gas tube, piston rings, or barrel gas port and without
increasing the cycle rate beyond a point where the magazine can
reliably feed. Such embodiments can be provided with small, cheap,
easy modifications to standard M16 and M4 production parts.
[0222] More robust long lugs are provided so that the firearm can
fire a more powerful cartridge, such as the 6.8 mm cartridge. The
6.8 mm cartridge applies 1.3 times the force on the lugs as
compared to the 5.56 cartridge, which the firearm was originally
designed to use. The increased surface are of the lugs is provided
by lengthening the bolt lugs and barrel extension lugs 1.35 times.
This provides the greater shear area and longer feed ramps, as
discussed herein.
[0223] The more robust locking lugs are provided without moving the
breach of the barrel forward. Moving the breach of the barrel
forward would undesirably either shorten the threaded length of the
barrel and reduce the strength of the barrel attachment to the
barrel extension or would require a longer barrel extension which
would need an unwanted change to the main gun body.
[0224] Rather, according to an embodiment, the barrel extension's
inner length and overall length are changed, while leaving the
outer length of the rearward face to the flange the same. No change
to the main gun body, barrel nut assembly and forward assembly,
sight block or gas tube is needed.
[0225] The features described herein can be used individually or in
any desired combination to provide a safer, more reliable firearm.
One or more of these features can be used to modify an existing
firearm. One or more of these features can be used to manufacture a
new firearm.
[0226] Comparisons are made herein to the standard M16. For such
comparisons, the standard M16 can be the M16 manufactured by FN
Manufacturing LLC (FNM), PO Box 24257, Columbia, S.C. 29224.
[0227] Comparisons are made herein to the standard M4. For such
comparisons, the standard M4 can be the M4 carbine manufactured by
Colt's Manufacturing Company Inc., Firearms Division PO Box 1868,
Hartford, Conn. 06144.
[0228] The standard M16 can be that defined by any M16 rifle
Technical Data Package (TDP) adopted by the US Military as the
standard for the M16 rifle, M4 carbine, or AR15 civilian model. The
standard M4 can be that defined by an M4 carbine TDP adopted by the
US Military as the standard when features differ from those of the
M16 rifle TDP.
[0229] Embodiments described above illustrate, but do not limit,
the invention. It should also be understood that numerous
modifications and variations are possible in accordance with the
principles of the present invention. Accordingly, the scope of the
invention is defined only by the following claims.
[0230] A firearm can comprise: a bolt having a plurality of locking
lugs, the locking lugs being configured to have a shear area that
is at least approximately 1.3 times that of a standard M16/M4; a
piston formed on the bolt and having a plurality of rings
configured to cooperate with the piston to mitigate gas leakage
past the piston, each of the rings having a key formed thereon and
a gap formed therein such that the gap of one ring is configured to
receive at least a portion of the key of another ring; a bolt
carrier to which the bolt is movably attached, the bolt carrier
having a double cut cam, the double cut cam having a starting point
in an unlocked position of the bolt that is substantially the same
as the standard M16 cam and having an unlocking cam surface that
has sufficient dwell increase to delay a start of unlocking when
the bolt carrier is used in an M16/M4 rifle or carbine; a weight
movably disposed within the bolt carrier, the weight being
configured to inhibit rearward and forward bouncing of the bolt
carrier; a carrier key attached to the bolt carrier and configured
to facilitate a stroke of the bolt carrier that is approximately
0.360 inch longer than that of the standard M16/M4; a buffer having
a length that is approximately 0.360 inch shorter than a standard
buffer for the M16/M4 buffer; a tube configured to provide gas from
a barrel of the firearm to the piston via the carrier key, the tube
having a heat radiator formed on at least a portion of the tube; a
gas metering plug having a gas metering hole configured to meter
gas from the barrel of a firearm to the bolt carrier of the
firearm, wherein the gas metering hole is located away from a gas
port of the firearm; and a front sight block having a rear band and
a front band for attaching the sight block to the barrel and having
a gas passage formed in the front band for facilitating gas flow
from the barrel to a gas tube of the firearm.
[0231] A bolt group can comprise: a bolt having a plurality of
locking lugs, the locking lugs being configured to have a shear
area that is at least approximately 1.3 times that of a standard
M16/M4; a piston formed on the bolt and having a plurality of rings
configured to cooperate with the piston to mitigate gas leakage
past the piston, each of the rings having a key formed thereon and
a gap formed therein such that the gap of one ring is configured to
receive at least a portion of the key of another ring; a bolt
carrier to which the bolt is movably attached, the bolt carrier
having a double cut cam, the double cut cam having a starting point
in an unlocked position of the bolt that is substantially the same
as the standard M16 cam and having an unlocking cam surface that
has sufficient dwell increase to delay a start of unlocking when
the bolt carrier is used in an M16 rifle or an M4 carbine; a weight
movably disposed within the bolt carrier, the weight being
configured to inhibit rearward and forward bouncing of the bolt
carrier; and a carrier key attached to the bolt carrier and
configured to facilitate a stroke of the bolt carrier that is
approximately 0.360 inch longer than that of the standard
M16/M4.
[0232] A device can comprise: a ring configured to cooperate with a
piston of a gas operated firearm to mitigate gas leakage past the
piston; a key formed upon the ring; and a gap formed in the ring
and configured to receive at least a portion of a key of another
ring; wherein the key is substantially opposite the gap on the
ring; wherein the key and the gap are formed such that a pair of
the rings is nestable with the key of each of the rings disposed
within the gap of each other of the rings; wherein the key is
substantially rectangular in cross-section; wherein the gap is
substantially rectangular in cross-section; wherein the walls of
the ring are substantially rectangular in cross-section; wherein
the ring is formed of stainless steel; wherein the ring is
configured to be received at least partially within a groove of the
piston; wherein the device is a firearm.
[0233] A device can comprise: a piston for a gas operated firearm;
a first ring configured to be received on the piston; a second ring
configured to be received on the piston; and wherein the first ring
and second ring are configured to interlock with one another such
that the first ring and second ring rotate substantially in unison
about the piston.
[0234] A method can comprise: placing one ring having a key and a
gap on a piston of a gas operated firearm; placing another ring
having a key and a gap on the piston; and wherein the key of each
one of the rings is disposed at least partially within the gap of
each of the other rings.
[0235] A method can comprise: mitigating gas leakage past a piston
of a firearm using a plurality of rings, each one of the rings
having a key formed thereon and a gap formed therein; and wherein
the gap of one of the rings receives at least a portion of the key
of another of the rings.
[0236] A device can comprise: a tube configured to provide gas from
a barrel of a firearm to a piston of the firearm; and a heat
radiator extending from at least a portion of the tube; wherein the
heat radiator comprises fins that form a V-notch with approximately
60 degrees between opposing walls; wherein the heat radiator
comprises threads;
[0237] The device wherein the tube has an outer diameter of 0.250
inch; wherein the tube is formed of 347 stainless steel; wherein
the tube is configured for use on a firearm having a piston formed
on a bolt of the firearm; wherein the tube is configured for use on
a member of an M16/M4 family of firearms; wherein the tube is
configured to receive gas from a barrel of a firearm that is a
member of an M16/M4 family of firearms via a front sight of the
firearm and to provide the gas to a bolt carrier of the firearm via
a bolt carrier key, the tube having an outside interfacing diameter
to the bolt carrier key of less than 0.1792 inches, the tube having
a length from a front sight mounting hole thereof to a rear end
thereof of less than 9.57 inches for an M4 type of firearm, and the
tube having a length from a front sight mounting hole thereof to a
rear end thereof of less than 14.95 inches for an M16 type of
firearm; wherein the device is a firearm; wherein the threads are a
uniform standard thread form; wherein the threads comprises helical
threads.
[0238] A method can comprise: cutting a tube; forming a radiator on
the tube; and installing the tube on a firearm such that the tube
is configured to provide gas from a barrel of the firearm to a
piston thereof; forming a first bend in the tube; and forming a
second bend in the tube; wherein the heat radiator comprises
threads; wherein the threads are uniform standard thread form;
wherein the threads are formed on a portion of the tube away from
ends of the tube; wherein the threads are not formed on ends of the
tube; wherein the tube has an outer diameter of 0.250 inch; wherein
the tube is formed of 347 stainless steel.
[0239] A device can comprise a tube configured to receive gas from
a barrel of a firearm that is a member of an M16/M4 family of
firearms via a front sight of the firearm and to provide the gas to
a bolt carrier of the firearm via a bolt carrier key, the tube
having an outside interfacing diameter to the bolt carrier key of
less than 0.1792 inches.
[0240] A device can comprise a tube configured to receive gas from
a barrel of a firearm that is a member of an M4 family of firearms
via a front sight of the firearm and to provide the gas to a bolt
carrier of the firearm via a bolt carrier key, the tube having a
length from a front sight mounting hole thereof to a rear end
thereof of less than 9.57 inches.
[0241] A device can comprise a tube configured to receive gas from
a barrel of a firearm that is a member of an M16 family of firearms
via a front sight of the firearm and to provide the gas to a bolt
carrier of the firearm via a bolt carrier key, the tube having a
length from a front sight mounting hole thereof to a rear end
thereof of less than 14.95 inches.
[0242] A method can comprise: providing gas from a barrel of a
firearm to a piston of the firearm; and wherein a heat radiator
extends from at least a portion of the tube.
[0243] A device can comprise: a gas metering hole configured to
meter gas from a barrel of a firearm to a bolt carrier of the
firearm; and wherein the gas metering hole is located away from a
gas port of the firearm; wherein the gas metering hole is located
sufficiently away from the gas port of the firearm so as to be
substantially unaffected by erosion; wherein the gas metering hole
is located sufficiently away from the gas port of the firearm so as
to be substantially unaffected by erosion caused by scrubbing of
passing bullets and/or bombardment of propellant grains; wherein
the gas metering hole is configured such that gas passes
therethrough prior to entering a gas tube of the firearm; wherein
the gas metering hole is smaller than a gas port of the firearm;
wherein the gas metering hole is formed in a plug at a front of a
gas tube; wherein the gas metering hole is formed of a heat
resistant material; wherein the device is a firearm.
[0244] A method can comprise: placing a gas metering hole in a path
of gas from a barrel of a firearm to a bolt carrier of the firearm;
wherein the gas metering hole is located away from a gas port of
the firearm; and wherein the gas metering hole is configured to
meter gas.
[0245] A method can comprise: metering gas from a barrel of a
firearm through a gas metering hole; providing the gas to a bolt
carrier of the firearm; and wherein the gas metering hole is
located away from a gas port of the firearm.
[0246] A device can comprise: a front sight block for a firearm; a
rear band and a front band for attaching the sight block to a
barrel of the firearm; and a gas passage formed in the front band
for facilitating gas flow from the barrel to a gas tube of the
firearm; the device wherein the gas passage is configured to
substantially align with a gas port of the barrel and to receive
gas from the gas port; can comprise a gas metering plug configured
to be received within the front sight block and configured to meter
gas from the gas port; wherein the gas metering plug comprises a
fixed orifice; wherein the gas metering plug comprises a calibrated
orifice; can comprise a gas tube configured to mate with the front
sight block; can comprise a heat exchanger formed upon the gas
tube; can comprise threads formed upon the gas tube; wherein the
front sight block is configured for use with a member of the M16/M4
family of firearms; wherein the device is a firearm.
[0247] A method can comprise: forming a gas passage in a front band
of a front sight block; forming a gas port in a barrel; and
attaching the front sight block to the barrel such that the gas
passage is substantially aligned with respect to the gas port; the
device can comprise installing a gas metering plug in the front
sight block; the device can comprise can comprise installing a gas
metering plug in the gas tube and installing the gas tube partially
within the front sight block.
[0248] A method can comprise: communicating gas from a barrel of a
firearm to a gas tube of the firearm; and wherein the gas is
communicated through a front band of a front sight block; the
device can comprise metering gas through a gas metering plug.
[0249] A device can comprise: a bolt carrier; a double cut cam
formed in the bolt carrier; and wherein the cam has a starting
point in an unlocked position of the bolt that is substantially the
same as the standard M16 cam and has an unlocking cam surface that
has sufficient dwell increase to delay a start of unlocking when
the bolt carrier is used in an M16 rifle or an M4 carbine; wherein
the device is a firearm.
[0250] A method can comprise: assembling a bolt carrier into a
firearm; wherein a double cut cam is formed in the bolt carrier;
and wherein the double cut cam has a starting point in an unlocked
position of the bolt that is substantially the same as the standard
M16 cam and has an unlocking cam surface that has sufficient dwell
increase to delay a start of unlocking when the bolt carrier is
used in an M16 rifle or an M4 carbine.
[0251] A method can comprise: moving a double cut cam with respect
to a cam pin from an unlocked position of a bolt to a locked
position of the bolt; and wherein the double cut cam has a starting
point in the unlocked position of the bolt that is substantially
the same as the standard M16 cam and has an unlocking cam surface
that has sufficient dwell increase to delay a start of unlocking
when the bolt carrier is used in an M16 rifle or an M4 carbine.
[0252] A device can comprise: a bolt carrier; a weight movably
disposed within the bolt carrier; and wherein the weight is
configured to inhibit rearward and forward bouncing of the bolt
carrier; wherein the weight is configured to slide within the bolt
carrier; wherein the weight is configured to impact an anvil after
the bolt carrier begins to bounce away from a forwardmost position
of the bolt carrier so as to inhibit bouncing of the bolt carrier;
wherein the weight is configured to impact an anvil after the bolt
carrier begins to bounce away from a rearwardmost position of the
bolt carrier so as to inhibit bouncing of the bolt carrier; wherein
the weight is configured to impact an anvil after a bolt engages
bolt lugs of a firearm so as to inhibit bouncing of the bolt
carrier; wherein the weight is configured to impact an anvil after
a buffer of the bolt carrier contacts a rear wall of a receiver of
a firearm so as to inhibit bouncing of the bolt carrier; the device
can comprise: a cavity formed within the bolt carrier and within
which the weight slides; and at least one spring configured to
generally center the weight within the cavity; the device can
comprise: a cavity formed within the bolt carrier and within which
the weight slides; two springs configured to generally center the
weight within the cavity; and two plungers upon which the springs
are disposed; wherein the weight is generally cylindrical in shape;
the device can comprise: a first cavity formed within the bolt
carrier and within which the weight slides; two springs configured
to generally center the weight within the first cavity; two
plungers upon which the springs are disposed; a second cavity and a
third cavity formed within the weight, one spring and one plunger
being disposed within each of the second cavity and the third
cavity; and wherein the second cavity and the third cavity have
blocking shoulders that prevent the plunger disposed therein from
moving beyond a centered position of the plunger so that when
inertia moves the weight beyond a centered position of the weight
one plunger compresses a spring to return the weight to center
while the other plunger and spring are blocked from acting upon the
weight; The device as recited in Claim 76, further can comprise an
anvil configured to hold the weight, the springs, and the plungers
within the bolt carrier; wherein the weight is configured to impact
against the anvil during forward and rearward travel of the weight;
the device can comprise a pin configured to hold the anvil at least
partially within the bolt carrier; wherein the bolt carrier is
configured for use in a firearm selected from the group consisting
of: a member of an M16/M4 family of firearms; a copy of a member of
an M16/M4 family of firearms; and any firearm in which the bolt
carrier will function; wherein the bolt carrier is modified to
function in guns that are driven by an operating rod and piston;
wherein the device is a firearm.
[0253] A method can comprise: providing a bolt carrier; movably
disposing a weight within the bolt carrier; and wherein the weight
is configured to inhibit rearward and forward bouncing of the bolt
carrier; wherein the weight is configured to slide within the bolt
carrier; wherein the weight is configured to impact an anvil after
the bolt carrier begins to bounce away from a forwardmost position
of the bolt carrier so as to inhibit bouncing of the bolt carrier;
wherein the weight is configured to impact an anvil after the bolt
carrier begins to bounce away from a rearwardmost position of the
bolt carrier so as to inhibit bouncing of the bolt carrier; wherein
the weight is configured to impact an anvil after the bolt engages
bolt lugs of a firearm so as to inhibit bouncing of the bolt
carrier; wherein the weight is configured to impact an anvil after
a buffer of the bolt carrier contacts a rear wall of a receiver of
a firearm so as to inhibit bouncing of the bolt carrier; the device
can comprise: forming a cavity formed within the bolt carrier such
that the weight is slidable with the cavity; and centering the
weight within the cavity using at least one spring; the device can
comprise: forming a first cavity within the bolt carrier such that
the weight is slidable with the first cavity; centering the weight
within the first cavity using two springs that are disposed upon
two plungers; and wherein the weight comprises a second cavity and
the third cavity that each have one of the plungers and one of the
springs disposed therein and that have blocking shoulders that
prevent the plunger disposed therein from moving beyond a centered
position of the plunger so that when inertia moves the weight
beyond a centered position of the weight one plunger compresses a
spring to return the weight to center while the other plunger and
spring are blocked from acting upon the weight; wherein the weight
is generally cylindrical in shape; the device can comprise: forming
a first cavity within the bolt carrier such that the weight is
slidable with the first cavity; forming a second cavity and a third
cavity within the weight; centering the weight within the first
cavity using two springs that are disposed upon two plungers;
wherein one of the springs and one of the plungers are disposed
within each of the second cavity and the third cavity; and wherein
the second cavity and the third cavity have blocking shoulders that
prevent the plunger disposed therein from moving beyond a centered
position of the plunger so that when inertia moves the weight
beyond a centered position of the weight one plunger compresses a
spring to return the weight to center while the other plunger and
spring are blocked from acting upon the weight; the device can
comprise using an anvil to hold the weight, the springs, and the
plungers within the bolt carrier; wherein the weight is configured
to impact against the anvil during forward and rearward travel of
the weight; the device can comprise using a pin to hold the anvil
at least partially within the bolt carrier; wherein the bolt
carrier is configured for use in a member of an M16/M4 family of
firearms.
[0254] A method can comprise: firing a firearm so as to cause a
weight to move within a bolt carrier; and wherein the weight is
configured to inhibit rearward and forward bouncing of the bolt
carrier; wherein the weight is configured to slide within the bolt
carrier; wherein the weight is configured to impact an anvil after
the bolt carrier begins to bounce away from a forwardmost position
of the bolt carrier so as to inhibit bouncing of the bolt; wherein
the weight is configured to impact an anvil after the bolt carrier
begins to bounce away from a rearwardmost position of the bolt
carrier so as to inhibit bouncing of the bolt carrier; wherein the
weight is configured to impact an anvil after the bolt engages bolt
lugs of a firearm so as to inhibit bouncing of the bolt carrier;
wherein the weight is configured to impact an anvil after a buffer
of the bolt carrier contacts a rear wall of a receiver of a firearm
so as to inhibit bouncing of the bolt carrier; wherein: the weight
slides within a cavity formed within the bolt carrier; and at least
one spring generally centers the weight within the cavity; wherein:
the weight slides within a cavity formed within the bolt carrier;
two springs generally center the weight within the cavity; the two
springs are disposed within two cavities upon two plungers; and
wherein the two cavities have blocking shoulders that prevent the
plunger disposed therein from moving beyond a centered position of
the plunger so that when inertia moves the weight beyond a centered
position of the weight one plunger compresses one spring to return
the weight to center while the other plunger and the other spring
are blocked from acting upon the weight; wherein the weight is
generally cylindrical in shape; wherein: the weight slides within a
first cavity formed within the bolt carrier; two springs generally
center the weight within the first cavity; the two springs are
disposed upon two plungers; one of the springs and one of the
plungers are disposed within each of a second cavity and a third
cavity formed in the weight; and wherein the second cavity and the
third cavity have blocking shoulders that prevent the plunger
disposed therein from moving beyond a centered position of the
plunger so that when inertia moves the weight beyond a centered
position of the weight one plunger compresses a spring to return
the weight to center while the other plunger and spring are blocked
from acting upon the weight; the device can comprise holding the
weight, the springs, and the plungers within the bolt carrier using
an anvil; wherein the weight is configured to impact against the
anvil during forward and rearward travel of the weight; the device
can comprise holding the anvil at least partially within the bolt
carrier using a pin; wherein the bolt carrier is configured for use
in a member of an M16/M4 family of firearms.
[0255] A device can comprise a bolt carrier having a weight
disposed therein so as to inhibit both forward and rearward
bouncing of the bolt carrier.
[0256] A method can comprise sliding a weight within a bolt carrier
so as to inhibit both forward and rearward bouncing of the bolt
carrier.
[0257] A device can comprise: a bolt for an M16/M4 firearm, the
bolt can comprise: a plurality of locking lugs formed upon the
bolt; a barrel extension; a plurality of locking lugs formed upon
the barrel extension; wherein the locking lugs are configured to
have a shear area that is at least approximately 1.3 times that of
a standard M16/M4; wherein the shear area is increased with respect
to that of a standard M16/M4 by lengthening the locking lugs; the
device can comprise: a flange formed upon the barrel extension such
that the flange is approximately 0.130 inch from a forward end of
the barrel extension; a carrier key configured to facilitate a
stroke of a bolt carrier within which the bolt is partially
disposed, the carrier key being approximately 0.360 inch longer
than that of a standard M16/M4; and a buffer having a length that
is approximately 0.360 inch shorter buffer than a standard buffer
for the M16/M4 buffer; wherein the device is a firearm.
[0258] A bolt group can comprise: a bolt having a plurality of
locking lugs; and wherein the locking lugs are configured to have a
shear area that is at least approximately 1.3 times that of a
standard M16/M4; wherein the shear area is increased with respect
to that of the standard M16/M4 by lengthening the locking lugs; the
device can comprise: a bolt catch; and wherein an over travel of
the bolt catch is approximately 0.355 inch so as to provide
sufficient time for the bolt catch to engage in an event of
increased fire rate; wherein a travel of the bolt is increased by
0.360 inch with respect to the travel of the standard M16/M4 to
reduce a rate of fire of a firearm.
[0259] A method can comprise: assembling a bolt for an M16/M4
firearm into the firearm; and wherein the bolt comprises a
plurality of locking lugs configured to have a shear area that is
at least approximately 1.3 times that of a standard M16/M4.
[0260] A method for operating a firearm, the method can comprise:
engaging locking lugs of a bolt with complementary locking lugs of
a barrel extension; and wherein the locking lugs of the bolt and
the locking lugs of the barrel extension are configured to have a
shear area that is at least approximately 1.3 times that of the
shear area of a standard M16/M4; wherein the shear area is
increased with respect to that of the standard M16/M4 by
lengthening the locking lugs; the device can comprise moving the
bolt with an over travel of the bolt catch of approximately 0.355
inch so as to provide sufficient time for the bolt catch to engage
in the event of increased gas pressure, firing rate, or bolt group
travel speed; the device can comprise moving the bolt with a travel
that is increased by 0.360 inch with respect to the travel of the
standard M16/M4 to reduce a rate of fire of a firearm; the device
can comprise feeding cartridges via two feed ramps that are longer
and wider than feed ramps of the standard M16/M4; the device can
comprise unlocking the bolt after approximately the same delay and
at approximately the same pressure drop as that of the standard M16
using a double cut cam.
[0261] A device can comprise: a carrier key configured to
facilitate a stroke of the bolt carrier that is approximately 0.360
inch longer than that of a standard M16/M4; and a buffer having a
length that is approximately 0.360 inch shorter buffer than a
standard buffer for the M16/M4 buffer; wherein the carrier key is
configured to attach to a bolt carrier with only one fastener;
wherein the carrier key is configured to avoid interference with a
portion of a lower receiver when the carrier and key are in a
rearmost position; wherein the device is a firearm.
[0262] A method can comprise: attaching a carrier key to a bolt
carrier for an M16/M4 firearm, wherein the carrier key is
configured to facilitate a stroke of the bolt carrier that is
approximately 0.360 inch longer than that of a standard M16/M4; and
placing a buffer in the firearm, the buffer having a length that is
approximately 0.360 inch shorter buffer than a standard buffer for
the M16/M4 buffer.
[0263] A method can comprise: cycling a bolt carrier for an M16/M4
firearm, wherein the carrier key is configured to facilitate a
stroke of the bolt carrier that is approximately 0.360 inch longer
than that of a standard M16/M4; and wherein the bolt carrier abuts
a buffer having a length that is approximately 0.360 inch shorter
buffer than a standard buffer for the M16/M4 buffer.
* * * * *